Source: The Wrestling Observer Newsletter
The reason Finn Balor has been working WWE live events but was kept off television is because WWE didn’t have a WrestleMania match for him.
For what it’s worth, Balor was originally penciled in to become the top of the babyface on RAW prior to his injury. This was going to be done to allow Roman Reigns to stay out of title contention until WrestleMania 33, but everything changed when Balor suffered the shoulder injury.
