The Costa Rican playmaker was sidelined for five weeks by a hamstring problem, but he returned for the Boxing Day draw with Southampton.
Jol insisted Ruiz was "influential" in the 2-1 win at West Brom on New Year's Day which saw the Cottagers pull six points clear of the Premier League relegation zone.
"We need five or six wins as soon as possible because all the managers of all these teams around us will worry because it is not a great position to be in," said Jol.
"But you saw at West Brom how influential Bryan Ruiz can be and he wasn't there for seven or eight games."
Jol also had positive reports on injured duo Damien Duff and Mladen Petric as he looks to guide Fulham into the top half of the table.
"Damien hopefully will come back next week and Mladen will come back," he added. "If we've got everybody on board, I think we are a good team, but, if not, then we struggle."