Garbutt, 26, was sent off in the 71st minute of his side's 38-4 loss for punching opponent James Tamou.
The Australian was banned for two games by the Rugby Football League on Monday.
"It's not something that I am about. I don't condone violence and I sought James out after the game to apologise," said Garbutt.
"I accepted the ban and I'm very disappointed I won't be out there with the boys for the next couple of weeks."
"Everyone that knows me knows I'm not the sort that does that kind of thing."
Leeds Rhinos prop Mitch Garbutt has apologised for his red card in Sunday's World Club Challenge defeat by North Queensland Cowboys.