Killie boss Jim Jefferies told PA Sport: "I got the letter from the chairman late this afternoon and it's great news for us.
"If anyone doubts his commitment then this has put it to bed.
"I think he had enough of all the speculation and after chatting with his mum and dad he made the decision to put it all behind him and do his best for Kilmarnock.
"And he has apologised to the fans for all the uncertainty.
"If a transfer happens, it happens but he is happy to stay with Kilmarnock and get on with his career.
"He's letting everyone know and there was no prompting from us."