Gardner played under him at Aston Villa and is now enjoying a career resurgence on Wearside. And he is unequivocal about the Ulsterman's qualities as a manager.
"The gaffer has come in here with a massive expectation after what he did at Villa," said the Sunderland midfielder. "He has only been here a year. Everyone is behind him. He's a top class manager with a top-class squad and I don't know why people are getting so hyped up about it "I have known and played under him for five years. To be with him every day of the week, I think I know him quite well. He's probably got more drive and determination now because he knows how well he wants to do. He knows everyone is behind him.
"The sort of changing room we have wants us to do well. We have a team full of fighters.
"Before Martin came I didn't want to be here. It's not only me, he's probably turned round the careers of two or three players here. He's done that for me - it's the things he does which people don't see. I am still here and still fighting because the gaffer is here. Everyone respects him, even the ones who aren't playing."