As noted yesterday, WWE has written Kevin Owens off of TV for the time being with an injury angle after Bobby Lashley attacked him on Raw and targeted his knee. While the injuries stated by a WWE.com article are part of the storyline, Owens evidently really is battling a knee injury for the last little while and is set to undergo minor surgery in the near future.
Reports have indicated that Owens is not expected to be sidelined for any extended period of time, but this actually won't be determined until he goes under the knife and surgeons are able to assess the situation. As a result, there is no timetable for his return as it would all depend on what they find. It is expected that either later today or this week, WWE will announce the surgery and perhaps offer up more details on how long Owens is expected to be out of action for.