The former Spurs boss admitted that, while he is pleased with his current squad, he is keen on adding more depth to his side as they enter another year of European football.
"I'm happy with the squad we have got, if they are fit," he told reporters.
"That is probably not realistic though so that's why we are looking for one or two additions."
The Dutchman is particularly interested in signing another striker, following Bobby Zamora's injury a year ago.
"It will be hard to find someone like [Zamora]. If Bobby is injured, we lack a number nine. On the other hand, Clint [Dempsey] can play that position."
Jol replaced Mark Hughes at Fulham earlier this summer after spending one season at Ajax.