"We have to pick ourselves up and there's not a situation where we can change the team in five or six positions," said Jol, whose side have dropped to within four points of the drop zone.
"And that means that a lot of players in my team have to play again and they've played a lot of games.
"There's a little bit of tiredness."
"If Mladen Petric had been fit then I probably could have played with him," Jol added.
"I played Diarra when he was 50% because he's an old war horse. But now he wants to get back to his full fitness and I feel that he's very close. If Diarra is back in there, it will be a very strong midfield again.
"Up front, we could have done with Petric because he can score out of nothing with his finishing.
"If these players come back, it will be like a fresh team, because we cannot play in our formation the last three months."