Malen has it out at Jonker after being branded "fat" by the former Gunners academy chief.
But Jonker told FOX Sport: "We found that he had to have a training delay for two months. He wasn't fit enough, that's what it was all about.
"In my eyes he's a great example for all those talents who think: what should I do now? At Arsenal he has been in a situation where it seemed to be over. He converted that attitude himself because he knew; this is not it and I have to change things."