Keane said: "I thought it was a brilliant challenge, I love the physical side of the game.
"You can always tell by player reactions and none of the United lads at the time, and players are best judges because they are nearest the tackle, didn't react over the top thinking it was a bad challenge, obviously at the end of it.
"When players are travelling that speed, defending like that, injuries are going to happen. I'm surprised there are not more like it. It was more of an accident at the end of with his trailing foot."