MLB September call-ups: Players who could have an impact in September

Edward Sutelan

MLB September call-ups: Players who could have an impact in September image

MLB teams are beginning to expand to the 40-man roster for the final time, for the league will eliminate the larger rosters in 2020. 

However, as long as it's 2019, teams will be able to benefit from the more crowded dugouts and cluttered bullpens. Many of the game's top prospects will have a chance to debut in the majors and some other minor league journeymen with breakout seasons could have a chance to prove their minor league numbers are for real.

There have been plenty of impactful September call-ups in the past who have made a big difference on a team's postseason run. Fred Lynn gave the Red Sox a preview at his talents in 1974. David Price became a shutdown relief option for Tampa on its way to a World Series in 2008. Billy Hamilton stole a few wins for Cincinnati in 2013. 

MORE: Yankees stay atop Sporting News' latest power rankings update

This list only contains players who have been promoted to baseball's highest level, but will be updated as more impact players are promoted.

Here are some of the minor leaguers promoted who could have a big impact on the playoff picture:

Gavin Lux

Unless the Angels or White Sox make an unexpected move and promote Jo Adell or Luis Robert, respectively, in September, there will be no prospect debuting in the majors more hyped than the Dodgers' second baseman. The numbers he put up in the minors this season are simply absurd. He played at both Double-A Tulsa and Triple-A Oklahoma City and combined to slash .347/.421/.607 with 26 home runs and 10 stolen bases. Upon his promotion to Triple-A midway through the year, he somehow got better, hitting to a .392 batting average through 49 games.

The Dodgers selected Lux in the first round of the 2016 MLB Draft, and he has delivered on the hype. MLB Pipeline has him listed as the No. 9 prospect in baseball while Baseball America has him at No. 6. It seems unfair, quite frankly, that the Dodgers should be so spoiled as to have a prospect like Lux waiting in the wings when they already are putting arguably the best product on the field of all 30 MLB teams. If they did have one weakness, it might be at second base, where Enrique Hernandez has just a 1.4 WAR — though he still has contributed with 17 home runs. Max Muncy had seen playing time there before his wrist injury, but now with Lux, it seems Muncy will mostly man first base when he returns. 

Lux should at least man the strong-side platoon at second base, batting left-handed to complement Hernandez's right-handed power. But certainly if Lux continues to dazzle like he has in the minors, it might be difficult to not play him every day.

Brendan McKay

There might not be a prospect in the minors more intriguing than McKay. A star hitter and pitcher for Louisville in college, McKay was selected fourth overall by the Rays in 2017 and was told he could both hit and pitch as he made his way to the majors. While he has done both, the pitching has far exceeded his production with the bat — and that's exactly why the Rays are excited to have him back in the majors for September. 

With uncertainty surrounding whether Blake Snell will be back and Tyler Glasnow still wrapping up a rehab assignment, the Rays find themselves in need of quality starting pitchers to push themselves into the playoffs. McKay has been, to put it mildly, untouchable in Triple-A this season and has looked respectable to this point in his eight MLB starts. He has recorded a 0.84 ERA at Triple-A and while the 5.55 ERA in the majors leaves a lot to be desired, peripherals such as FIP, xFIP and SIERA have his expected ERA to be somewhere in the low-4.00 range. McKay, the No. 14 MLB Pipeline and No. 11 Baseball America prospect, should pick up several starts in September. And with his elusive array of pitches and plus control, he could be someone who could win a few games for Tampa Bay.

Nate Lowe

The Rays have already received outstanding production from one infielder with the last name of Lowe (same spelling, different pronunciation). How about call up another one? Nate has slashed .289/.421/.508 with 16 home runs in 93 games at Triple-A this season and is considered among the best first base prospects in the game. Lowe has already spent time in the majors this season, accumulating six home runs in 32 games with a promising .889 OPS. 

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With Brandon Lowe out for the season, the Rays could use some left-handed thump to add to their lineup as they wind down the season in a tight battle Cleveland and Oakland for a wild card spot. Nate Lowe is viewed by evaluators as a batter who could post an average in the .270-.290 range while providing 20-plus home runs in a full season of work. Ji-Man Choi has certainly put together a breakout season so far in Tampa and should still be the regular starter at first, but Lowe gives the Rays an extra bat off the bench and a left-handed option to Avisail Garcia at designated hitter. 

Brusdar Graterol

If you managed to catch Graterol's MLB debut on Sunday, you saw why the 21-year-old has made quick work of the minors. A right-handed flamethrower in the Twins' organization, Graterol was signed in 2014 and, after only having reached Advanced Class-A in 2018, shredded Double-A in nine starts there this season. After a shoulder injury sidelined him for two months, Graterol returned as a reliever and saw more success. He was fast-tracked through Double-A and just four games in Triple-A before Minnesota called him up.

Graterol's long-term future might be as a starting pitcher, but at least for the rest of this season, the Twins will want to use him only as a reliever. With a plus-plus fastball that routinely touches triple-digits and a wipeout slider, Graterol should have no trouble giving big league batters fits and helping solidify Minnesota's position atop the AL Central. He's had issues with walks in the past, but with strikeout rates near 30 percent in the minors and the ability to handle the workload of a starting pitcher, Graterol could be a shutdown pitcher for multiple innings per outing.

Kyle Tucker

In terms of prospect hype and minor league production, Tucker is right up there with Lux. Listed as the No. 12 prospect per MLB.com and the No. 10 guy by Baseball America, the Astros' outfielder has long been one of the most exciting outfield prospects in the minors. He has only built upon that in 2019 by posting a 30/30 season with 34 home runs and 30 stolen bases to accompany a .266/.354/.555 slash line. Despite the hype, he had been passed over for a promotion earlier in the season for Yordan Alvarez, a decision made by the Houston front office that has paid off with Alvarez looking like the favorite to win American League Rookie of the Year.

Playing time could be tough to come by for Tucker. With outfield and DH options of Alvarez, George Springer, Michael Brantley and Josh Reddick, there's not much room for Tucker to make an impact, particularly given that he, Alvarez, Brantley and Reddick all swing from the left side of the plate. Scouts believe the 22-year-old prospect will post a high batting average and contribute above-average power — though they are not sold on the speed being much more than slightly above average. With Houston having already essentially locked up its place atop the AL West, Tucker could fill in for some of the other outfielders to spell them before the postseason run. If he lives up to the hype, he could even force his way onto the Astros' playoff roster as a potential star bat off the bench.

Kevin Cron

Not every player who appears on this list is considered a "prospect," but Cron's numbers at Triple-A this season would have you believe he's something special. Ranked as just the 26th best prospect in the Diamondbacks' system by MLB.com, Cron put up ridiculous stats in 2019, slashing .331/.449/.777 with 38 home runs in only 82 games — a pace of 75 home runs in 162 games. A corner infielder by trade, Cron might be best suited for first base, but with Christian Walker — another older minor leaguer excelling in his first taste of the majors — already manning the position, Cron would likely shift over to third base in Arizona. 

The Diamondbacks certainly have no chance of competing with the Dodgers for this year's NL West title, but the wild card is still well within grasp for Arizona. They have received another year of sterling production from Eduardo Escobar in his first full season in the desert, but he has more positional flexibility and could shift around a bit more with Cron spelling him at the hot corner from time to time. Still, the Diamondbacks' infield is loaded, with Nick Ahmed having a nice year at shortstop, Ketel Marte having an All-Star campaign at second and Walker putting up some solid numbers at first base — all four infielders pace the team in WAR. But if Cron can add a potent bat to the bench or serve as a way to not lose any production while giving a starter a day of rest, the Diamondbacks will gladly take it as the season winds down.

Sean Murphy

When Murphy was drafted in the third round of the 2016 draft by Oakland, he was viewed as a glove-first catcher whose bat might eventually be enough to make him a regular. The defense from the 24-year-old backstop remains among the best of any catcher in the minors, but it's his bat that could really make a difference for him and the Athletics as the Green and Gold battle for that wild card position. Murphy's biggest battle this season has been with injuries, as he has been placed on the injured list twice. Despite a knee surgery and a second knee injury later, Murphy has looked promising when he's played, recording a 1.011 OPS with 10 home runs in 31 games at Triple-A this year. 

The Athletics are once again in contention, and manager Bob Melvin has suggested Murphy should not be expected to surpass Josh Phegley as the starter behind the dish. But with the 31-year-old posting a lukewarm .709 OPS across 94 games, Murphy could be a potential offensive upgrade while flashing his extremely promising defensive prowess. If nothing else, having a reliable backup catching option can assure Melvin that he can rest Phegley without losing much production at the key position down the stretch.

Clint Frazier

It came as a surprise to some that Frazier was sent back to the minors with the return of Aaron Judge. Frazier had become a steady presence in the Bronx Bombers' lineup during his time in the majors, posting an .826 OPS with 11 home runs in 55 games. Certain peripherals like his 6.5 percent walk rate and 27.4 percent strikeout rate suggest regression is a possibility. He did struggle when he went back to Triple-A, but the tools are there for him to be an impact bat.

The Yankees have no shortage of outfield options and bats, with Judge, Aaron Hicks, Mike Tauchman, Brett Gardner and Edwin Encarnacion, but there's still uncertainty for when Giancarlo Stanton will return. Scouts have long raved about the potential in Frazier's bat, at one time receiving average grades on his hit tool, plus-plus grades on power and above-average marks for speed. If he can give New York an extra bat off the bench down the stretch to preserve some of the Yanks' other starters, he could provide them with more than average production.

Cole Irvin

Contrary to Alzolay, this Phillies' southpaw will not light up the radar gun and lacks the usual prospect hype. Irvin is listed as the No. 16 prospect in Philadelphia's system, with the report saying his fastball typically sticks in the low-90s range. Results matter, and Irvin has posted respectable numbers in Triple-A this season, owning a 3.94 ERA in 93.2 innings with only 14 walks to 65 strikeouts. 

Irvin is not going to be the flashy pitching name that Spencer Howard might be for Philadelphia, but the rotation in the City of Brotherly Love is hurting for some quality arms. The starters own a collective 4.57 ERA and rank 23rd in WAR. The bullpen has been worse, recording a 4.65 ERA and placing 27th in WAR. Irvin could provide some much needed help.

Junior Fernandez

Originally progressing through the minors as a starter, Fernandez was shifted to the bullpen to preserve his arm and keep him healthy after some arm woes kept him sidelined for extended periods. Opening 2019 for his first full season as a reliever, Fernandez has been lights out at every stop along the way, compiling a 1.52 ERA in 45 games across three minor league levels with 80 strikeouts in 65 innings. He routintely runs his fastball up near the triple-digits and has a fadeaway changeup that gives him a plus secondary offering to keep hitters off balance.

The rich keep getting richer, as the saying goes, and that applies to St. Louis' bullpen. The Cardinals are tied for sixth in bullpen WAR and their combined ERA is second-lowest in baseball at 3.62. With plenty of high-octane options already, such as Carlos Martinez and Giovanny Gallegos, Fernandez becomes the latest reliever who can turn in a shutdown inning. And as the Cardinals cling to a division lead against the Cubs, it will be imperative to have options like Fernandez fresh down the stretch and ready to enter the playoffs.

Edward Sutelan

Edward Sutelan Photo

Edward Sutelan joined The Sporting News in 2021 after covering high school sports for PennLive. Edward graduated from The Ohio State University in 2019, where he gained experience covering the baseball, football and basketball teams. Edward also spent time working for The Columbus Dispatch and Cape Cod Times.