With a transfer deadline day that didn't quite go to plan, Fulham have been left with a threadbare central midfield and the scenario has been worsened by the news that Diarra, now a linchpin in Jol's plans, could potentially miss up to six months of action with news still pending on his knee injury.
After losing Danny Murphy, Moussa Dembele, Dickson Etuhu and Marcel Gecov - among others - over the course of the summer, Jol had plans to boost his midfield numbers on the last day of the window. He had his eyes on, particularly, Vadis Odjidja-Ofoe and Wilson Palacios, but a deal for the former fell through while a move for the latter was not completed in time.
The crisis in numbers led to the signing of Giorgos Karagounis and the deployment of the versatile Chris Baird in the middle of the park. So far, Baird has impressed while Steve Sidwell has held fort well, but Karagounis has yet to feature.
And, with the successful signing of Diarra in the past, Jol is not afraid to delve into the free transfer market again in the near future.
"As you know," Jol told the Fulham Chronicle, "when there was an opportunity with Karagounis we did that, there was an opportunity last year with Diarra and we did that. If there's an opportunity to get a good player in we will do that."
More than likely, the Dutchman has three particular players in mind - Nigel Reo-Coker, Thomas Hitzelsperger and Owen Hargreaves.