Fulham manager Martin Jol has admitted that he made a mistake by starting Bryan Ruiz against Blackburn Rovers on Sunday.
The £10.6m signing from FC Twente had a debut to forget and was substituted at half-time.
"In hindsight, I would have started Mousa and then brought him on because he's good when there's a lot of pressure on the goal, space in the box, and Bryan Ruiz probably would have given us a lot second half," he said.
"I wouldn't say it's a gamble but you have to start somewhere and that was a decision we had to make and I made the decision to play him.
"But, of course, it's a different tempo and he lost the ball a couple of times."
Fulham take on FC Twente in the Europa League at Craven Cottage tonight, but Ruiz is cup tied and won’t play in the competition until the next stage.