Ole Gunnar Solskjaer has admitted he will probably sanction the departures of "one or two" more players before the January transfer window closes.
United have already sold defender Timothy Fosu-Mensah to Bayer Leverkusen this month, with striker Odion Ighalo also likely to leave when his loan expires in less than a fortnight.
A number of other fringe men could be on the move, as Sergio Romero, Marcos Rojo and Jesse Lingard are all looking for new clubs.
Lingard was left out of the squad against Liverpool on Sunday, as too was winger Dan James, who could yet leave on loan.
"I don't want to go into individuals but we can probably allow one or two more to go out," Solskjaer said.
"But one of the strengths we have is we have a deep squad, strength in depth. We don't want to give our advantage away by easing off on our players.
"So I can't really give you a better answer than that."
French Ligue 1 side Nice were in talks with Lingard over a potential move but have since cooled their interest as the club's president, Jean-Pierre Rivere told fans not to expect "big names" this month.
The midfielder is expected to stay at Old Trafford until the end of the season, when he will enter the last 12 months of his contract.
Meanwhile the future of James is up in the air amid recent interest from four Premier League clubs.
West Brom, Leeds, Brighton and Burnley are all keen on signing the 23-year-old on a temporary deal.
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James has only made 10 appearances this season for United, but whether Solskjaer would be open to letting him go is another question.
The exits of Romero and Rojo are more conceivable, neither of whom are considered part of the first-team plans at United.
Both players have been linked with a return to Argentina with Boca Juniors, while Romero has also been attracting interest from Major League Soccer franchises in the U.S.
