The summer signing from Ajax has impressed under Rosenior since his appointment.
"In my time, he's been magnificent," Rosenior said in the build-up to this weekend's game at Everton.
"I've been so impressed with his temperament, his physicality, technically. He is a joy to work with every day, and at his age, it’s scary how good he could be.
"It takes time. He's a young player that came through at Ajax, who captained Ajax at 17 years old. He then joins a massive club in a different league, in a different culture, and it takes time to bed in.
"In terms of what's happened before me, there are loads of different contextual things that can affect a player's performance, but in my time with Jorrel, he's earned my trust, he's earned the staff's trust, and he's a very, very exciting player."
Rosenior also enthused: "I think he could play pretty much any position on the pitch, which normally Ajax-educated players can do.
"If he stays with his temperament and keeps improving at this rate, the sky's the limit for him."