There is a distinction between having a "mental disability" and "not feel[ing] like himself mentally right now to play in Philadelphia and need[ing] time," and that distinction makes a difference to the tune of 34 million dollars.
The CBA treats a mental disability that prevents a player from playing the same as a physical disability - as it should. For Simmons to show that he has a mental disability that prevents him from fulfilling his obligations under the contract, "not feeling like yourself" is not going to cut it. Nor will experiencing stress and anxiety associated with the prospect of going through an awkward or uncomfortable experience (i.e. facing teammates or a home crowd after you publicly demanded a trade and then tried to hold out to force said trade).
If Simmons' goal is to continue to be paid and avoid joining the team, he's going to have some challenges.
First, while the CBA puts mental and physical disabilities on the same footing, arbitrators and judges are much more skeptical of mental disabilities given the subjective nature of such complaints (soft tissue injuries are just a step above). Second, you have the prior inconsistent statements regarding the reason for his hold out. Granted those would not actually be in evidence because none of them were said by Simmons directly, but its naïve to think those leaks and "reports" are not going to have some impact on your fact finder. Third, just like with a physical disability Simmons will need medical confirmation of the disability. What's the diagnosis? How long has be treating? How often does he see his provider? What meds have been prescribed? How many times has the dosage or med been adjusted?
If Simmons has been in treatment for some time and has good answers to those questions, he can prevail. If not, it will be an uphill battle. I am somewhat skeptical that he has those ducks in a row, because if he did, that's the card Klutch should have played first: Klutch advises the Sixers in writing that Simmons is claiming a mental disability; Klutch cites to the relevant provision in the CBA and if the Sixers fail to pay him, Klutch grieves it.
However, that's not what Klutch did. They demanded a trade, at first in private and then in public. Then Klutch made it clear Simmons would not report or never play a game for the Sixers again. Based on the reporting, it appears that Klutch under took strategy under the (mistaken) belief that because of the payment structure in Simmons' contract, he would not be negatively impacted by any fines until November at the earliest. The problem with that assumption is that it ignores the concept of an "anticipatory breach" which you learn as 1L. With the installment payment being stuck in escrow and (unrecoverable - per the Union) penalties being deducted from it with every missed game and practice, Klutch reversed course and had him report. Then he gets tossed from practice and suspended a game (costing him more money), and now we have this new strategy.
If I were crediting Klutch, with playing chess instead of checkers, maybe they don't plan to rely on the disability language in the CBA. Maybe invoking his mental health now is not an effort to have him stay home and still get paid, but rather is Klutch setting up an affirmative defense of sorts. Maybe Simmons will eventually report, practice and play. However, he will be sluggish, disengaged, etc. If the Sixers try to push back with fines, suspensions, Simmons has an answer at the ready: "I told you I was not at 100% mentally, this is the best I can do." That would put Morey in a box.
