During WWE RAW on Monday night, Samoa Joe teamed with Kevin Owens to face RAW Tag Team Champions Seth Rollins & Buddy Murphy for the titles.
At one point during the match, Joe hit a dive and grabbed the back of his head. He was then pulled out of the match and taken to the back. Owens ended up finishing the match by himself, however was ultimately pinned by Murphy.
PWInsider reports that the injury was 100% legitimate and WWE medical personnel made the decision to pull him from the bout. After Joe was removed, the rest of the talent were calling the match on the fly.
Joe was evaluated backstage after the match. Dave Meltzer reported on Wrestling Observer Radio that the belief is that Joe suffered a concussion, although that is not definite yet.
Joe had just returned to action last month after suffering a thumb injury last September.
Source: Wrestling Inc.