There's a reason Bobby Lashley targeted the knee of Kevin Owens on Raw.
According to John Pollock of POST Wrestling, the angle was done to give Owens time off for knee surgery. The injury does not appear to be major and Owens is not expected to miss much time.
Following the attack on Monday Night Raw, WWE put out a statement on their website saying, "Kevin Owens sustained injuries to both knees when Bobby Lashley viciously wrapped Owens’ legs around a turnbuckle after their match, WWE.com can confirm. Owens will undergo further evaluation tomorrow to determine the full extent of the damage."
Owens lost to Lashley on Raw in singles competition. Following the bout, Lashley wrapped Owens' leg around the ring post at the encouragement of his manager Lio Rush.
The angle worked as a double turn as Lashley received boos for his actions while Owens was cheered and turned into a sympathetic babyface.
On Tuesday, WWE announced that Owens is out of Mixed Match Challenge and a replacement partner for Natalya Neidhart will be needed.