Trotta has been playing on-loan at Brentford this term.
"He did very well at Wycombe - didn't score 20 goals, but he made a step," Jol told fulhamfc.com. "Now he went to Brentford and he made another step. Of course it is not the Barclays Premier League but for me it is important that the young players get games and make progress and, for me, Alex [Alexander Ka?anikli?] did that, [Kerim] Frei did that. And of course Trotta did the same.
"For me it is important that the players show a good mentality and that they want to play and improve themselves. Of course he has the skill: the finishing, he is a goal poacher, but there are certain other areas to his game which he can improve and hopefully he will do that."