The Costa Rican, who joined Fulham from FC Twente in 2011, has scored just five goals for the club this season.
"He is one of my better players. He's always playing for the team and looking for runners to give that last pass," Jol told The Sun.
"Maybe we need another passer. The thing is you miss him in midfield and if he's not up front, he's playing too deep. That is my dilemma."
Fulham currently sit 12th in the Premier League table.