"It's the attitude I've got and the attitude most should have," the 25 year old told BBC Newcastle.
"If you're in the starting 11 then you should be happy with that."
Gardner continued: "Why should we moan about playing in a different position when they're prepared to pay to watch us play?”
"It's competition all over the pitch, if it wasn't we wouldn't be competing for the top eight," Gardner added.
"We want to put our own players under pressure because we don't want people thinking they will automatically be picked.
"It's not healthy, the lads are not going to improve."
"When I first came here my head wasn't in the right place," Gardner added.
"I just wanted to finish training and get home. That was me missing home really, but I had to man up.
"Martin came in and I've known him a long time, it's about seven years now, and that helps.
"I know what he wants in the changing room and on the pitch and hopefully I can give that to him."