Berbatov has netted just two goals for the Cottagers this season, and despite being employed in a different role during this campaign, Jol has revealed that he is expecting the Bulgarian to "come up with the goods".
The 57-year-old told GetWestLondon: "Dimitar should do better than he did before. I have enough experience with him, he is always someone who will score one in two or one in three, but don't forget that he has had to do a different job for the team.
"He has had to play in the hole and he's probably more like a number nine who likes his freedom. Of course, he's not a real box player like the big target man in England, but he's certainly a goal scorer.
"If he wasn't here last season, we would have had a problem, especially after Clint Dempsey left. He was our main goalscorer so Berbatov knows that he is an important player to us but he must come up with the goods."
Berbatov's place in the Fulham starting lineup could be in doubt when the Cottagers host Manchester United on Saturday.