The Cottagers are 10th in the Premier League table ahead of the weekend matches, but still only nine points above the drop zone on 33 points.
Stoke, West Ham, Newcastle and Norwich are all level on points with Fulham and Jol reckons any one of them could yet find themselves in trouble.
"We are in a good position but you have to look over your shoulder," said the Dutchman.
"Four or five clubs are still with us there who could be dragged into a situation you won't like.
"We always say we would like to get 40 points as soon as possible and then, you never know. Last year we had 52 points and the year before we were in the top eight with 49, so hopefully we will get 40 and then a bit more."
At White Hart Lane Jol will come up against Gareth Bale, the player he brought to Tottenham from Southampton as a 17-year-old in 2007.
Spurs are being tipped as potential title contenders over the next few seasons and Jol admits the in-form Welshman will be key to their chances.
"They were 12 points ahead of Arsenal last season and at the end behind them so they were not consistent enough to contend for the title," he added.
"They are the same as they were the year before, but at some clubs you have the luck of having a player like Bale, making steps and getting better, so that is why they get better."