There have been a lot of questions regarding the status of Christian after suffering a concussion in the Fatal 4-Way Match on this week's episode of Monday Night Raw off an errant kick from Alberto Del Rio.
Because it's Christian's second concussion within a calendar year (with the other being suffered on August 26, 2013 in a match against Randy Orton), Christian must undergo a one on one evaluation by Dr. Mark Lovell. This is the same specialist that Dolph Ziggler had to see before he gained medical clearance when returning from his second concussion within a calendar year. Dr. Lovell is based out of the University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania.
Additionally, Christian will have to be asymptomatic and pass an ImPACT Concussion Test before being cleared to return.
For more, look over the WWE & ImPACT Concussion Management Program.