O'Hoppe was removed from Friday's game against Boston with a head injury, Jeff Fletcher of The Orange County Register reports.
O'Hoppe took a foul tip off his mask during the third inning of Friday's contest and was immediately replaced behind the plate. It remains unknown whether the 26-year-old suffered a concussion as a result of the incident, though he has had problems with concussions in the past. Tyler Heineman entered the game as O'Hoppe's replacement and would presumably start any games the latter has to miss.