The injury occurred when Sin Cara ducked a clothesline and sent Corbin out of the ring. After the spot Cara landed awkwardly on his leg, which he was then seen clutching in pain. The referee communicated the injury to Sami and Corbin and they did the finish of the match, which saw Corbin getting the pinfall victory on Zayn.
As of this writing, WWE has not released a statement on his injury. We will keep you updated.