Wanderers' top scorer was needlessly sent off in his last outing against Norwich for an apparent head-butt on Marc Tierney.
Klasnic has spent the last 10 days on international duty with Croatia, and, while his manager is happy to put the incident in the past, he has left the striker in no doubt that his behaviour must improve.
"We've had a chat because he knows what he did on that day hurt us," Coyle said.
"I still feel we would have got something from the game with 11 men, and we very nearly did with 10.
"There's no doubt he was remorseful for what happened to his team-mates. But what has happened, has happened.
"He's been away with Croatia, and although he was in the squad for both games, didn't get any game time. So he'll be back, refreshed and raring to go."