Former Manchester United midfielder Darren Fletcher believes the club will find it tough to finish in the Premier League's top four without further recruitment.
Ahead of the transfer window closing on October 5, Ole Gunnar Solskjaer's side have been linked with a number of players including Jadon Sancho, Luka Jovic and most recently Barcelona attacker Ousmane Dembele.
Borussia Dortmund star Sancho has been a long-time target for the Red Devils but they have struggled to get a deal done.
United have signed just one player so far this summer in the form of Dutch midfielder Donny van de Beek and Fletcher is adamant more recruitment is needed if the club want to be competitive.
"We know it's more difficult for Manchester United to sign players. The value goes up, the negotiations are difficult," Fletcher told Sky Sports.
"But at the same time they will be frustrated - Ole, the fans, everybody around the club - by the fact that Chelsea and other teams can do their business early, and that other teams have spent a lot of money already while Manchester United look like they are going to leave it last minute.
"For me, Ole Gunnar Solskjaer, for the job he has done for the club, from where it was to what it is now, deserves the players he wants in. He's always got the best interests of the club at heart, I know that, but sometimes Ole has to look after himself as well, because he's going to be judged season on season.
"People don't look at the work you've done, they want the here and now, and for Manchester United to get to where they want, they need players. They need three, four, five players to get anywhere close to challenging Liverpool. If they don't recruit, they are going to find it tough to finish top four.
"I would hate all that pressure and criticism to go on Ole Gunnar Solskjaer, because I feel he's done a fantastic job.
"The board have to back him. Ole will have identified targets and so will the club. They've got five or six days to get him some help and get him some players in."
After losing their first game of the season against Crystal Palace, Solskjaer's side have bounced back with consecutive wins over Brighton and next face Tottenham in the Premier League on Sunday.