Scott Parker admitted Fulham club captain Tom Cairney is "struggling" with an ongoing knee problem and could face weeks on the sidelines.
Cairney has not featured for Fulham since the 1-1 draw at Newcastle on December 19, with Joachim Andersen taking the armband in his absence.
Parker said before the Chelsea game on January 14 that Cairney had a slight knee issue after missing the FA Cup third-round clash with QPR and the league game against Tottenham, but the injury seems to have worsened.
"He's struggling a little bit at the moment, Tom," the Fulham manager said.
"He's got an ongoing issue at the moment and it's becoming a little bit of a problem really, so we're going to refer him and get to see some specialists and get an opinion on that.
"I don't foresee Tom being around for probably a few weeks from now at the earliest, and I probably won't have a clearer picture on that until we really get some information back from some specialists."
Fulham host Burnley in the FA Cup fourth round on Sunday, which could be an opportunity for some players to get game time as the squad are also preparing for their third successive midweek clash at Brighton on Wednesday.
Both matches will have to take place without captain Cairney, although his manager is hopeful he will not require surgery.
"I don't think it's going to be the option," Parker said.
"Like I said it's a problem that players get and we just need to manage the pain, strengthen that area a little bit and see where he is.
"But at the moment it's proving a bit too painful and we need to work out whether there's other avenues we can take as a medical team to speed up the process and we'll go from there."