Berbatov required an injection to play in the second half at the Madjeski Stadium but Jol has revealed that his £5m striker will require an X-ray on the rib injury.
Jol said: "He needed an injection to play the second half and showed a lot of character.
"There was a problem with his rib which was very painful. Maybe it was broken; we'll have to take a look at it.
"We asked him to play on for 10 or 15 minutes but he stayed on the pitch and it was good to see him score the third goal."
Berbatov has scored three goals in five appearances for Fulham since his move from Manchester United during the summer.