The Costa Rica international has been sidelined for a month so far with a hamstring injury, a spell which has coincided with a drop in form for Jol's side.
The Fulham boss revealed that Berbatov is feeling the strain leading the line on his own and hopes Ruiz can return to action sooner rather than later.
He told The Mirror: “Dimitar [Berbatov] knows how important Ruiz is to us. Berbatov has been filling in that role of a No.10 and it was a bit of a surprise at the start of the season that he could play there.
“At one stage, he covered 12 kilometres [in a match] and it was a record for him. But you have to get the ball up to your best players and they play in the front four.
"We were one of the best teams in the league last year, that is what I want and that is what Berbatov wants.
“The evidence lies in the fact that every time Bryan Ruiz plays, we have scored more goals than when he isn’t. So, it’s simple.”Fulham visit Anfield this weekend and Jol faces a reunion with Luis Suarez. The Fulham boss made the Uruguayan his captain during their time at Ajax and the striker repaid his manager by firing his side to the Dutch title.
When asked about working with the Liverpool striker, Jol simply said: “He was exceptional for me at Ajax.”