The former Southampton midfielder has played just three times in the Premier League this season, each appearance coming from the bench.
The France international is not in Jose Mourinho's plans and Everton have made contact with United to discuss a deal for the player.
No official agreement has been made yet, and it is thought that United want to recoup the £25m that they paid Southampton for the France international.
Everton are also thought to be keen on Memphis Depay, who is also surplus to requirements after a disappointing debut season.