Defender Jonathan Spector has extended his stay at Birmingham after penning a new two-year deal.
Bastian Schweinsteiger’s Bayern Munich future remains in doubt after Matthias Sammer admitted he could leave the club.
Ross Barkley has returned to Everton after the midfielder's loan deal with Leeds came to an end.
The youngster was not involved in the squad that lost 1-0 at Middlesbrough on Tuesday night, and he has now returned to Goodison Park.
"I spoke to David Moyes at Everton," United boss Neil Warnock told the club's official website. "He wants him to play and I couldn't guarantee him that.
"He's done well, he's a smashing player, but he needs to play games and I can't guarantee that."
The Everton youngster joined the club on January 11 and made four appearances during his short stay with the club.