Hargreaves has made just 39 appearances for United since joining the club in the summer of 2007.
The former Bayern Munich star has just six months left on his contract at Old Trafford.
Hargreaves has been struggling with knee problems during his time at United and his last attempt at a comeback against West Brom in October ended after five minutes with a hamstring injury.
The Sunday Mirror reports that United will allow Hargreaves to leave on a free at the end of the season.
