IMO the biggest onfield issue is that the club hasn't strengthened the team where it's lacking most obviously, namely at LB and CB. Guðmundur arrived, yes, but we don't know if there's a player there, and to pretend that Matarrita is good enough is just to hide your head in the sand. Also, Chanot's sell-by date has passed. To me it seems that he has some attitude problems, and another commanding CB would have been a very important purchase. Sands can do the job, but we don't know how he progresses, and you cannot rely on just one player. Ibeagha is a solid replacement for Chanot, but the club does need an upgrade there.
Medina is less of an issue, because he can always be left out of the team, although I feel that at Columbus that wasn't possible, and he was there to make up the numbers. Cue his quick substitution after the sending-off.