The source notes that the injury was "a pull in the groin area," and tests last week revealed that the injury was more serious than originally thought.
Going into the weekend, WWE's creative team apparently wanted Henry to be given a lighter workload for the next few weeks to allow the injury to heal. Vince McMahon nixed that and made the decision to do a title change. Most people expect Daniel Bryan's title reign to be short-lived due to this.
Brian "Road Dogg" James noted last week that Henry was taken to the hospital to "have his ankle scoped".
More as we get it.