Former Boyzone band member Gately was found dead in Mallorca nine days ago and Gray was accused of distasteful remarks by Coventry striker Leon Best while team-mate Gunnarsson left the field with a broken leg.
Gray, who has also apologised to Gunnarsson for trying to get the Icelandic midfielder to his feet after the challenge by Leon Clarke, said: "Obviously I did not realise Aron Gunnarsson's injury was a bad one at the time and I'm 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 Aron's injury is not a serious one and I wish him a speedy recovery."
On Best's allegations, Gray added: "Anyone who knows me knows I would not conduct myself in that way.
"I find it disappointing that another player would suggest I made those kind of comments. The words that have been published are misleading and way off the mark and I dismiss them completely."