From WWE.com:
WWE Superstar Christian suffered a concussion during a match with WWE Champion Randy Orton on the Aug. 26 edition of Raw, according to WWE physician Dr. Chris Amann.
“We’ve pulled him out of all activity,” said Amann. “His ImPACT scores are normal, but he’s still having some symptoms of fogginess and cloudiness.”
He continued, “We are waiting for symptoms to get better until we perform an in-ring exertional challenge later this week at the Performance Center in Orlando. At that point, if he’s able to get in the ring and exert himself, and work without symptoms, we’ll go ahead and clear him [to compete].”