Manchester United striker Robin van Persie believes that fatigue could play a part in Monday's FA Cup quarter-final replay against Chelsea with both teams having played two games in the space of 48 hours.
After a 3-3 draw at Old Trafford, the two clubs will meet again at Stamford Bridge just two days after their latest Premier League fixtures on Saturday.
|20/1||Brede Hangeland is 20/1 with Bet365 to score first for Fulham against QPR
"We are ever so satisfied that he signed his contract because you never know," Jol told reporters. "It was quite challenging trying to keep him.
"I thought I could lose him - and he was a tower of strength this year, last year and before I came here. I always thought he wanted to stay, but you never know.
"He was on a free at the end of the year and it took a long time. But we did everything and in the end it was a happy outcome.
"He came to sign it on Thursday and it was a relief. He is one of the best players in the division, he is our skipper and a very nice man. So, we're very pleased to keep him."
QPR, who make the short journey to face Fulham on Monday night, were one of the clubs thought to be eyeing a move for Hangeland should he have failed to agree terms.
The Hoops tempted Bobby Zamora to Loftus Road in the summer but Jol insisted that he did not regret allowing the striker to leave.
"Bobby wanted to move," he claimed. "He thought he could help QPR and, if he's fit, he can help any team as he's a good striker."