Fulham, Blackburn Rovers, Burnley and Wolverhampton Wanderers are all said to be interested in McNair, who has only started three Premier League games this term.
However, Louis van Gaal is said to be keen on keeping the Northern Irishman at Old Trafford.
McNair enjoyed a promising debut campaign at Man United last season as he was drafted in to the first-team following an injury crisis during the first half of the campaign.
The youngster was solid at centre-back and right-back and he would have been hoping to build on his performances this time around.
However, McNair has found chances harder to come by this term, despite the fact that United have suffered a number of injuries at the back.
Like James Wilson, perhaps a loan move for McNair would be best in terms of his development. Including a call-back option would allow United to bring him back to the team if they get to stretched in defence.