Mowbray said: "I've had a lot of conversations with John almost on a daily basis. I have no problems with him. He's a nice guy but as a footballer he's a little bit short at the moment. Yes, John is frustrated. Yes, he wants to play football and there is a desire from both parties to try and resolve the situation but it's not easy because of the contract John has. It has to suit both parties and until it is resolved, John has to get on with it."
Hartson is believed to be a target for Swansea.