Hey at least he was really hurt I think this was just a sensible precaution given the timing of the trade and break.
But unfortunately he may not be 100% the rest of the year. Rivers also said something about him being healthy enough to play but not practice (which, teams barely practice at this point anyway but obviously there is a reason to do so now).
That might be the big risk going forward (and it's what already happened to the Nets to some extent): the Sixers have their two stars, but they might never both be fully healthy at the same time. One is fragile and one is old. Really, it's astonishingly lucky, at least from a Negadelphian perspective, that Joel isn't Bynum or Oden.