Fantasy Baseball Trade Report: Top buy-low, sell-high candidates for the second half

With the All-Star festivities in the rear-view mirror, the home stretch of the 2023 MLB season begins Friday night. For fantasy baseball owners, the postseason push now starts to intensify. Frontrunners will do all they can to maintain their positioning, the middle of the pack will be gunning for the top seeds, and the teams around the bubble will wheel and deal to get back into the race. Every acquisition becomes more important from here on out, so let's start the unofficial "second half" of the MLB season off by highlighting some fantasy baseball buy-lows and sell-highs.

The optimal move when assessing and evaluating the buy-low and sell-high market is trading a sell-high guy in exchange for a solid buy-low candidate. Imagine if you acquired Juan Soto or Julio Rodriguez earlier in the season when they were struggling and all you had to give up for one of them was Bryan Reynolds. Both outfielders started the season in brutal slumps while the Pirates third baseman was among the top-ranked offensive players in baseball.

The same can be said for Blake Snell and Kyle Freeland. The Padres veteran was awful in April while Freeland was amazing. Fast forward to mid-July and Snell is the No. 83 player in Yahoo head-to-head category league while Freeland is ranked 1,022nd (who would have thought the success of a career 4.32 ERA guy would be unsustainable at Coors Field?). You get the point. Don't ride out a high you know won't last when you can grab a guy who's been a stud in the past (hey look, I'm a poet).

Enough of the yada yada -- let's improve our rosters! Here are the top buy-lows and sell-highs ahead of the second half. Good luck, have fun, and go make the playoffs!

Fantasy Baseball Trade Report: Best buy-low candidates for the second half

Ownership rates and rankings courtesy of Yahoo

Carlos Correa, SS, Twins (77% rostered)

Correa has fallen a long way since his World Series heroics in 2017 and second All-Star appearance in 2021. Entering the All-Star break, the Twins shortstop ranked 518th in Yahoo category leagues, 397 spots below his preseason ranking of 121. It probably wouldn't take much to acquire Correa from his frustrated fantasy owners, and we would highly recommend starting to make some low-level offers now. 

Don't look at Correa's .225 average on the season — that's what you should hope his owners do — you should be looking at his .324 average and 15.7-percent strikeout rate over the past nine games. He has seen the ball much better over the past few weeks, and the run production and power numbers should follow. The dude is batting leadoff for a potential playoff team, with players like Byron Buxton, Alex Kiriloff, and Max Kepler behind him. He's not going to finish the season with 60 runs and 80 RBIs.

Get creative and offer up an early-season waiver-wire gem who has cooled off considerably, like Christopher Morel of the Cubs or even Correa's Twins teammate Willi Castro if you already have ample stolen base production. If you need help in the batting average department and want to gamble on a former All-Star seeing positive run-scoring and RBI regression, you can't find a better buy-low than Correa.

Max Muncy, 2B/3B, Dodgers (65%)

Muncy started the season sizzling hot, leading the majors in home runs well into May. However, he fell into a funk over the past month, hitting just three of his 21 round-trippers while dropping his season-long average to a measly .198. Many fantasy owners have started to hit the panic alarms on Funky Muncy, desperately offering trades in search of more dependable contact hitters. 

If you're looking for power, swoop in on the Munce-man now. Let's not forget that the third baseman started the 2022 season off much worse, posting a .164 average, .319 slugging percentage, and just nine homers in the first half. In the second half, despite playing 10 fewer games, he compiled nine more extra-base hits, nine more RBIs, and three more homers. His slash line was obviously much more impressive, too: .230/.340/.451. In 2021, he hit 17 of his 36 home runs in the 66 games after the All-Star Game, finishing fourth in the NL. 

Muncy will always ding your average, but if you're relatively comfortable in that department, he's a worthwhile buy-low while he's still in his Munce-funk. The guy has as many home runs as NL MVP frontrunner Ronald Acuña. One torrid stretch and he's right back to producing top-30 fantasy numbers for a hot Dodgers squad that just took back over first place in the West. If you play your cards right -- say, dealing a hot hitter with little pop like Philly's Alec Bohm — you could be one of the owners benefiting from his second-half bounce-back.

Nick Castellanos, OF, Phillies (96%)

Castellanos has established himself as one of the best hitters in the sport, and he just played in his second career All-Star Game. However, he's just the No. 160 player on Yahoo over the past 30 days, mostly due to his .256 batting average and measly eight runs during that span. Now is the time to capitalize and try to bring the slugger in via trade, even if you have to deal away a couple of young risers.

Look at Castellanos's first-half and second-half slash lines and strikeout rates from the 2022 season:

Those are some sharp increases, which led to solid power numbers when he was on the field in the second half. Since he did miss some time due to injury last year, we'll give him a mulligan on the five home runs he hit in the second half. Take away last season, and you'll see that Castellanos has hit no fewer than 13 home runs in the second half of any season since 2018. The Phillies, like the Dodgers above, are about to go on a hot streak. You might want to sell your George Springer, Teoscar Hernandez, and Luke Raley stock now so you can buy into the artist known as Castellanos. 

Justin Verlander, SP, Mets (98%)

Verlander's reputation precedes him. He's won an MVP, three Cy Young Awards, two World Series, two ERA titles, and the pitching triple crown. However, many fantasy owners feel the ace has finally landed on the other side of the dreaded "hill" nobody wants to go over. At the midway point of 2023, he's just 3-4 with a 3.60 ERA, 1.20 WHIP, and 57 strikeouts across 70 innings. Somebody call fantasy pitching 911 — he's old!

Well, let's pump the brakes a tad. Verlander has taken some time to get hot plenty of times throughout his career, and his best stuff more often than not comes out when the games become more meaningful. Just look at his numbers in the second half of 2022: 6-1, 1.51 ERA, 0.75 WHIP, and 10.6 K/9. He was even more dominant in the latter part of 2019: 11-2, 2.06 ERA, 0.79 WHIP, 13.7 K/9. Need more evidence? Twelve of his 16 wins in 2018 came after the All-Star break.

Verlander may be a little long in the tooth at 40, but he still knows how to pitch better than 98 percent of major league pitchers. He's always worth a buy-low if somebody is foolish enough to sell him. In fact, I would trade our very first sell-high guy for Verlander in a New York minute.

Fantasy Baseball Trade Report: Best sell-high candidates for the second half

Shane Bieber, SP, Guardians (98% rostered)

The sell-high window might have already closed on Bieber, who's suffered four bad starts since June, but there are more than enough sellable numbers for motivated owners who want to ship him out. He did have eight strikeouts in two of his past four games, he pitched seven shutout innings with nine strikeouts against the Astros on June 11, and his ERA is still a very serviceable 3.77. He's the No. 150 starting pitcher on the season. 

That's a far cry from his No. 37 finish last year, but his 11 quality starts this season is right on pace with his final tally of 23 last season, so just emphasize the good and discourage the negativity during negotiations. He's only 28 and just a few years removed from the AL Cy Young, you'll say. Stud pitchers with his skill sets always have strong second halves.

That last part isn't even a lie. He had a 9-3 record, 2.48 ERA, and 0.94 WHIP in the second half of 2022 compared to a 4-5 record, 3.24 ERA, and 1.13 WHIP in the first half. But those first-half numbers aren't even that bad, while his 2023 has been a combination of good and completely atrocious. What worries us the most is the Biebs' sudden inability to miss bats. His strikeout rate is down below 20 percent for the first time in his six-year career. He's also getting hit harder than he ever has, allowing an average exit velocity of 91.3 miles per hour and a 46.3-percent hard-hit rate. 

Maybe the pitch clock has messed up Bieber's rhythm. Maybe he's just fatigued or has some underlying mental or physical issue we don't know about just yet. Whatever it is, we're not waiting around to find out. We would trade the Biebs for the aforementioned Justin Verlander or his teammate Max Scherzer. Maybe package Bieber and a top-30 bat for injured Rays ace Shane McClanahan and hope to hit the jackpot once Mac gets off the IL (back tightness). We would gladly take a veteran enjoying a strong year like the Padres' Blake Snell, Rangers' Nate Eovaldi, or Twins' Sonny Gray. Hell, give us the Red Sox's Brayan Bello! Any above-average pitcher will be better than what we fear Bieber's season will turn into in the coming months.

Corbin Carroll, OF, Diamondbacks (99%)

I know, I know. I've been singing his praises all summer, and suddenly I'm advocating for you to sell him to the highest bidder in mid-July. But shoulder injuries are no friggin' joke, and Carroll has experienced press-stopping pain in his surgically repaired shoulder not once but twice in the past month. This kid is 22 and Arizona already threw a massive bag at him to lock him up for the long term. There's no way Torey Lovullo and the D-backs' management team risk his future by continuing to play him if that shoulder gets hurt a third time. 

Players at Carroll's age rarely come up with speed, power, and contact-hitting skills anymore. We get how excruciating it can be to deal away a Rookie of the Year frontrunner, but as tough of a pill as it is to swallow, it's a necessary one if your team is struggling and you need to win now. He's ranked No. 215 over the past two weeks and No. 169 over the past month. Do you want to stick around and see how low he will dip if his injury gets worse, or, even worse, if he misses time? He's still the No. 6 player in all of fantasy on the season, so now is the time to try to acquire an established top-10 talent, such as Fernando Tatis Jr. or Manny Machado, who almost made our buy-low list. 

Maybe you can package Carroll and another good hitter like San Diego's Xander Bogaerts or the Cubs' Nico Hoerner and make a play for Reds' rookie phenom Elly De La Cruz. As good as Carroll has been this season, EDLC is a league-winner. Those scoffing at the thought can check back with me on Twitter in a few months and tell me if they're still scoffing. 

Ketel Marte, 2B, Diamondbacks (92 percent rostered)

Marte is the No. 37 in cat-leagues thanks to a .286 average, 15 homers, 44 RBIs, and six steals, but the D-backs started staggering toward the All-Star break and Marte's sudden decrease in production was either partly at fault or an unfortunate byproduct. The infielder ranked No. 442 in the week before the ASG and No. 813 over the past two weeks. Good lord, that's some dooky rankings.

While we recommended selling the Cubs' Christopher Morel for Correa earlier, we would advise buying Morel if you can get away from Marte by emphasizing his strong overall season and calling this stretch "just a slump." His strikeout rate is rising toward 30 percent, so get out while you still can before the D-back house is fully ablaze (as in "the house is burning down," not "this club is on fiiiiiiiyaaaaaah!"). 

Vladimir Guerrero Jr., 1B, Blue Jays (99%)

This one's a bit of a reach, as Vladdy isn't exactly on a "high," per se. He's the No. 81 player in all of fantasy, No. 270 over the past two weeks, and No. 511 leading into the All-Star Game. But he just won the Home Run Derby, and people who lead their fantasy squads with their heart and not their head might be inclined to buy into a second-half bounce-back. 

Spoiler: We're not buying. While he's hitting the ball as hard as ever, his home run rate (3.4 percent) and isolated power (.169) are lower than they have been since his rookie year. He's popping the ball up a ton, either because he's late on swings or getting under balls too much. His sweet-spot percentage — basically how often he hits the ball with the optimal part of his bat — is 33.6 percent, which ranks 161st out of the 268 MLB hitters who have logged an at-bat this season.

The faster pace may have messed with the 250-pound slugger's rhythm, and we would strongly suggest talking up his hard-hit and exit-velo numbers — not to mention his Derby win — while trying to land a more serviceable option like the Guardians' Josh Naylor or D-backs Christian Walker (hey, a Diamondback we're buying and not selling!). Hell, if I could get another piece paired with him, I might even consider bringing in Spencer Steer for Vladdy.