So Fish will be sanctioned?
Since the new rules started in 2009, tens of players withdrew from so-calleds "mandatory tournaments" without having any real reason. Not especially American players, for instance Albert Montanes was the specialist to skip the summer hardcourt tournaments.
I don't think Fish is stupid enough to be the first one in that case.
Moreover, from what I heard, he's had real issues, probably more than Roddick actually.
In reality, no tournament is mandatory, the only matter players don't like about so-called mandatory tournaments is that they get zero point in their rankings which they can't replace with a result in another tournament, but there's no real imposition contrary to what some players say to the media.