Jose Mourinho admits he is "worried" over the current contract situation surrounding Manchester United midfielder Marouane Fellaini.
Fellaini's contract is due to expire at the end of the season after United activated a one-year extension earlier this year, leaving him free to speak to other clubs in the January window.
And Mourinho, who also has defender Luke Shaw nearing the end of his own deal next year, has revealed his concern at the possibility of Fellaini becoming a free-agent in the summer.
"I'm worried about Fellaini and not about Luke Shaw because Fellaini finishes his contract and Luke Shaw doesn't," Mourinho said.
Fellaini joined Manchester United from Everton for £27.5m in September 2013 and has become an important player during Mourinho's reign at Old Trafford.
The midfielder scored four goals in eight starts for the club this season before injuring his knee on duty for Belgium against Bosnia and Herzegovina on October 7.
Juan Mata, Ander Herrera, Daley Blind and Ashley Young are all coming to the end of their own contracts at United with each having the option to a further one-year extension, which the club indicate will be triggered.