During Monday Night Raw yesterday, the angle with Lashley, McIntyre, and Corbin destroying Strowman’s elbow was a coverup for an injury he is dealing with at the moment.
Dave Meltzer of the Wrestling Observer said that Strowman has bone spurs in the elbow and will be undergoing surgery, putting the match against Corbin at TLC in jeopardy. The match was announced on Raw last night in the opening segment and Corbin in fact mentioned that Strowman might not make it to TLC due to the handicap match he set-up, which was then changed to a six-man tag match.
The situation will be evaluated once Strowman is opened up and his elbow is surgically repaired. Typical recovery for removal of bone spurs is around a week or two for regular individuals but it could take up to six weeks for a more-damaged elbow.