Manchester United are serious about securing French international Youssouf Fofana.
The defensive midfielder is attracting the attention of several Premier League clubs.
However, United may be the ones with the greatest need, given the poor form of Casemiro this season.
United see the 26 million-rated Monaco star as an ideal acquisition, most likely in the summer.
Casemiro may move on from the club by that stage, while Sofyan Amrabat's loan move from Fiorentina is unlikely to be extended to a permanent deal.
Fofana is only 24, but has already shown that he can thrive in pressure environments.