The Maltese striker, who is on the transfer list and can talk to clubs in January due to his contract expiring in June, has only scored once this season at Wolves for the Sky Blues.
"Michael worked so hard against Swansea but it was just the end product again," said Coleman to the CT. "You can say that he doesn't always have the end product and he is not going to be at this club forever, but you can't fault his workrate because he does work hard for the team.
"But the left-back for Swansea was never comfortable against him. "He's so quick and he needs to keep running as fast as he is but he needs to think a little bit slower because when he gets to the final ball he is still working at 100 miles an hour.
"He had a burst of goals last year and then he hit a brick wall and he thinks it was because he was moved out wide.
"But if you play a 4-3-3, even the wide guys get into a central area when they get chances, and we have made a lot of chances as a team and should have scored more than we have, but maybe it is a mental block with him at the minute."