As someone who suffers from cluster headaches I feel his pain. I get them the same time of year every few days for about a month, then they're gone until next year (episodic). Some people have them all the time (chronic). They are excruciating and not a lot of great treatments (oxygen and some nasty drugs. Regular paid meds don't help). I can see him not being able to play,even with treatment, until his cluster period ends.