Pure speculation at this point. Crew medical information is confidential unless released specifically by that crew member.
Drudge is being sensationalist at this point. It could very well be any of the other crew members. I will say that space sickness generally hits new astronauts and those who haven’t been in space in a while (Schlegel and Eyharts, are the latter, Love, Melvin and Poindexter are the former). It also hits older astronauts worse than new astronauts.
Speculation is also around that it could be another astronaut and Schlegel is the one that is best suited to replace that astronaut, see the fact that he’s still going to be the second crew member on EVA 2.
Plus, Admin, can you either a) take this out of breaking or b) change the title if you leave it in breaking.