The £3.2million striker has played just 32 minutes of football as a substitute since arriving on transfer deadline day from Watford.
Coyle told the Bolton News: We know how well the lad is training. When he came in, the strikers had hit some form and then when we looked to play him, he was stop-start with the FA Cup.
"Coming out of that we've hit a bit of form again and taken 13 points from the last 21. Of course, Marvin will be frustrated; I am frustrated for him.
"But what we do know is he is set for a magnificent future and that's why we brought him to the club."