Management seems totally incapable of handling any situation professionally. This isn't that hard of a problem. If he has an issue wearing the logo, you meet with him, let him know that you appreciate his concerns and will try to work with him to address the situation. But you also lay out the facts that he has a contract with the club, that the club has a contract with the sponsor, and that those contracts present certain limitations on what each party is entitled to do. If they can reach a reasonable resolution within the confines of those limitations, great. If not, then promptly do what needs to be done to mitigate the harm to the club. Above all, do it quickly, and do your best to keep it out of the press.