Louis van Gaal has refused to rule out the possibility of letting Darren Fletcher leave Manchester United this month.
Fletcher, whose current contract expires this summer, has been linked with moves to West Ham, West Bromwich Albion and Valencia. West Ham are interested in a permanent deal while Valencia want a loan move, sources have told ESPN FC.
The Scotland captain has made 13 appearances for United this season but has not featured since the FA Cup third-round win over Yeovil and has only started one Premier League match since August.
"It is the transfer month, so you never know," said Van Gaal in a news conference, when asked if he would accept a bid for Fletcher.
The 30-year-old, who has made 350 appearances for United, is the longest-serving player at Old Trafford and, as Van Gaal noted ahead of Friday's FA Cup trip to Cambridge, the only one to have won the competition at the club.
Fletcher was appointed vice-captain in the summer, only for Van Gaal to subsequently make Michael Carrick the deputy to skipper Wayne Rooney.
"He is a player of Manchester United [at the moment]," Van Gaal added. "That is the update and Darren Fletcher is the only player who has won already the FA Cup in my selection. He is also my captain, one of the three."
Van Gaal, who has been criticised for using a back three, insists he is flexible in his tactics and weighs up the pros and cons of a midfield diamond, where his experience has shown that there are more chances at both ends of the pitch.
He added: "We have [played] for example 4-4-2 in a diamond, we have played five or six matches. We have created a lot of chances but we have also conceded a lot of goals against us, and that is the balance of the team, and as a manager you have to look to that.
"OK, we have won more than ever in this system so I am willing to play that, but you have to see against which opponent and also I have to keep my team in balance."
Information from ESPN FC's Miguel Delaney was used in this report