MANCHESTER, England -- Jose Mourinho has admitted there is a chance Marouane Fellaini could leave Manchester United in the summer.
The midfielder is out of contract at the end of the season and will leave Old Trafford for nothing if a new deal is not agreed.
He is free to negotiate with overseas clubs from January -- although sources have told ESPN FC the Belgian, who rejected an offer in September, will not be sold during the transfer window.
Mourinho says he is "worried" Fellaini could go and he accepts there is nothing he can do to influence the 30-year-old's decision.
Asked at a news conference on Friday what he can do to turn the situation around, Mourinho said: "Nothing. It is a discussion between the player and the board.
"I'm not involved in contracts in deals, and I respect both, I respect the player because he has the right, has the right to decide his future, and I respect the board because the decisions and the discussions are under control so I just wait, wishing they will have an understanding but it's out of my control."
United face Brighton at Old Trafford on Saturday in what will be their first league meeting since March 1983.
Brighton have risen to ninth in the table on the back of a five-game unbeaten run. Mourinho's team also play Watford and Arsenal next week.
It is a chance for United to make up some ground in the title race after slipping eight points behind Manchester City.
Mourinho will be without Phil Jones and Eric Bailly against Brighton but Paul Pogba is set to start his third game in a row.
Mourinho added: "We cannot think about the gap, we cannot think about the gap to City, we just have to focus on ourselves and the matches.
"It's probably the first time this season with three Premier League matches in one week, with a couple of days in between matches, but you know I think every team is prepared for that, even when I look to teams with other ambitions I see fantastic squads so I think the teams are going to cope with the week."
"For us Brighton, Watford and Arsenal is a very important week but let's focus on Brighton, ninth in the table, good team, difficult to beat, don't concede many goals, has a mix of physicality, aggression, quality creativity and I think Chris [Hughton] is doing a great job.
"We must focus on this one. I know we have a good record at home and are strong at home but the opponent is going to be difficult for us."