Gardner is facing "the biggest game" of his career when he returns from suspension for Sunday's clash with Tottenham at White Hart Lane on Sunday.
Blues are only above the bottom three on goal difference from Blackpool and Wigan, who visit Manchester United and Stoke respectively.
Nine-goal leading scorer Gardner told Press Association Sport: "The Carling Cup win was fantastic and it's something we will never forget. To lift a trophy for the fans and the club after so long was fantastic. But this game is our career, it's bigger than the cup final and we need to go out there and give it every single ounce for this club."
He added: "On a personal level this has been my first full season at Premier League level and it's been a great season for me.
"But I'd give up every single goal now just to stay in the league. In fact, I'd give my winners medal back to stay in the league.
"If we end up in the Championship next season, it's a failed season for me.
"We owe it the fans, we owe it the gaffer (Alex McLeish). Everyone owes it each other to go out there and put a performance on."
Source: PA
Source: PA