The Cottagers saw a number of key players leave in the summer and, after a bright start to the campaign, have dropped down the table.
Fulham welcome Wigan to west London tomorrow as they look to build on their recent win at West Brom, but Jol is aware he needs to improve his squad.
Central midfield is a key area for the Dutchman, who revealed the Cottagers are also after cover at right-back as Stephen Kelly is on the verge of joining Reading.
"As a lot of other teams will tell you, we are very close [to bringing in players] but there are so many other teams involved," Jol said.
"If you want a good player, other teams are there to try and jump on it so we have to be very inventive.
"We don't have a lot to spend, to be honest, so we have to be very creative.
"It'll be not good to tell you the areas we need to strengthen but we try to get one or two players in to strengthen the squad.
"One example is right-back as Stephen Kelly, who went for a medical at Reading today. It is close to completion. I expect him to join Reading permanently."