With their place in the top four at risk, former Manchester United midfielder Darren Fletcher believes the club must bring in up to "five" players this window.
United have made just one signing, with Dutch midfielder Donny van de Beek arriving from Ajax. The club have been heavily linked with Jadon Sancho throughout the window, but a deal does not look like it will materialise, with alternatives, such as Barcelona forward Ousmane Dembele, being looked at.
Former United defenders Gary Neville and Rio Ferdinand have been highly critical of executive vice-chairman Ed Woodward and the United hierarchy's inability to get deals done, with Fletcher the latest to add his voice to the discontent.
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"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," Fletcher told Sky Sports.
"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 criticism to go on Solskjaer, because 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.
United, who booked a place in the League Cup quarter-finals with a 3-0 win over Brighton on Wednesday, host Jose Mourinho's Tottenham in the league on Sunday.
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