Jol's men have claimed just one point from their last five fixtures after their third straight defeat at Goodison Park on Saturday and the manager is aware of the need to improve next season.
The Dutchman told reporters: "We will always find players like Mladen Petric or Hugo Rodallega.
"But, of course, it's not easy. I think we had five new players in, so it's not easy to settle.
"I'm satisfied we've got the points to be safe, although I'm a bit disappointed we couldn't get more points in the last few weeks and gone even higher."
Fulham were linked to Swansea City's Wales and Great Britain full back Neil Taylor over the weekend. The 24-year-old has just made his first appearance since September after recovering from a bad ankle injury.