According to Dave Meltzer, the reason Seth Rollins didn't compete on Monday night's episode of RAW was because he broke his little finger during a Street Fight with Erick Rowan at a WWE Live event on Sunday (that would explain the tape around his fingers).
Apparently, the original plan was for Rollins to square off with Cedric Alexander but that was scrapped.
There was also talk of Rollins taking on Kevin Owens at TLC but with no official announcement, it seems like the latter's storyline injury is being used as a way to delay the match even though Rollins has reportedly been cleared. Chances are WWE won't want to make it worse, though!
Interestingly, it's noted that Rollins' match with Alexander was going to play into his heel turn.