there is nothing wrong with asking professional atheletes, in ANY sport, to appear as anything other than professional when representing their team in public.
When I was in high school (many years ago), even our football team had to dress up on game day. They all had red blazers and they looked very nice. You could tell they took pride in being a member of the team. Professional (and I use the term very loosely) athletes have become a disgrace over the past few years. I don't think it's asking too much for these overpaid, spoiled brats to wear decent clothes when representing their team.
Now they should also make a ruling against chocking the coach and sex with minors (e.g. DeShawn Stevenson serving alcohol to and then raping a 14 year old girl).