Fulham have suffered an injury blow with the news that John Arne Riise could face a lengthy spell on the sidelines.
The Norwegian defender was forced from the pitch as Fulham qualified for the Europa League group stages on aggregate despite a 1-0 defeat by Dnipro.
And Jol has admitted he could lose the player for some time.
"Riise has a serious problem with the leg," he said. "That's why I substituted him with Matthew Briggs."
The injury took the gloss from Fulham's progression to the group stages of the competition after a difficult night in the Ukraine.
They eventually won on aggregate after weathering wave after wave of attacks on a difficult pitch.
Riise joined the Cottagers in July, signing a three-year contract after leaving Italian side Roma for an undisclosed fee.
He has made six appearances this season - including both of the club's Premier League fixtures - but will now have to sit out with Briggs likely to get a run in the team.
The 20-year-old has impressed this term and was rewarded with a call-up to the England under-21 squad for their matches against Azerbaijan and Israel in September.