@LG
"Mind you, it did not help his case much to be photographed gambling in a casino, since gambling is prohibited by muslim law as well, as I understand it..."
No doubt Cisse was congratulated on the PR success of his stance but, nevertheless, advised that (i) it's not his duty in life to speak on behalf of his faith - that's the Imam's job and he should stick to the footie duties, in future (ii) excessive piousness generally goes down badly with the guy in the sky...
I have no idea what the Qu'ran has to say about honouring one's contracts. If it's in there, maybe that's what clinched the deal and convinced him to wear the shirt?