Said Gray to Sheffield Wednesday's official club website: "Obviously I did not realise that Aron Gunnarsson's injury was a bad one at the time and I am sorry for what happened.
"It was something that happened in the heat of the moment and if I had known the player had potentially sustained a serious injury I certainly would not have tried to get him to his feet.
"I hope that Aron's injury is not a serious one and I wish him a speedy recovery."