As noted, King Barrett confirmed on Twitter that he's been away this week due to an injury and noted that he's rehabbing some nerve damage in his neck.
Barrett will return to WWE TV on this Thursday's SmackDown, so it looks like he won't miss much TV time. He appeared in a segment with The League of Nations at tonight's tapings in Newark, New Jersey and did get somewhat physical.
WWE SmackDown spoilers for this week are here. For those who missed them earlier, here are Barrett's tweets on the injury:
Rehabbing a little nerve damage in my neck at the moment, hence the disappearing act. Nothing major, but not worth taking unnecessary risks.— Stu Bennett (@WadeBarrett) December 15, 2015