Wayne Rooney shrugged off his role in Jason Knight's injury and said: "That's football".
The Ireland midfielder found out last week that he will be sidelined for up to three months with an ankle injury.
But it only emerged this week that Derby County boss Rooney inflicted the damage when contesting a 50-50 ball in training.
Manchester United legend Rooney has been forced to join in during Rams training matches because Derby have so few players available.
And quizzed on how he crocked Knight, Rooney said: "It was a training ground incident and I demand intensity.
"Players get injured and unfortunately Jason did, but that's football. I demand that we train like we play."
Knight, 20, has won six caps under Stephen Kenny and will miss September's World Cup qualifiers against Portugal, Azerbaijan and Serbia.
