The 28-year-old midfielder grew up as a Blues fan and despite starting his career with their arch rivals Aston Villa, completed his childhood dream by spending a season with the club in 2010-11.
He now goes back as part of a West Brom team looking to build on a promising start to 2015 under new Baggies boss Tony Pulis.
Birmingham City v West Bromwich Albion
The FA Cup
Fourth Round Proper
3pm, Saturday 24 January 2015
St. Andrew's, Birmingham City FC
Winners receive £90,000 from prize fund
And as one of the few local players involved in this game, Gardner has been letting his team-mates know just what is at stake for the fans.
"Obviously, Birmingham City is extra special for me," said Gardner.
"I was there as a player and I'm a Blues fan, so I know about the bragging rights on the streets and the kids going to school and the adults go to work and it's just big for the area - I can't wait.
"The new manager [Gary Rowett] there has come in and he was a fantastic player for the club, he knows what the Birmingham City fans want and the passion and belief that they've got.
"It looks like he's brought that into the team and the players have reacted and they're doing so well now in the league."
But Gardner’s past loyalties will be put to one side now as Albion aim to continue their unbeaten run since Pulis’ arrival.
"You want to do well in The Cup, especially The FA Cup because it's a great competition to be involved in," he added.
"We’re unbeaten in four now, so we just want to keep that run going in The Cup."
As Gardner alludes to, the arrival of former Stoke City and Crystal Palace boss Pulis at the Hawthorns has seen the team revitalised.
Pulis has never been relegated his managerial career and Gardner explains how he’s made an instant impact on the squad.
"When you see what he's about on the training pitch and in the dressing room, you can see why he's never been relegated," revealed the former England Under-21 player, who joined Albion from Sunderland last summer.
"He gets the best out of players and he works so hard on the training pitch to get it right for when it comes to the Saturday, so there's no distractions or excuses.
"That's your job - do it. It's really drummed into us, where he wants us to be when they've got the ball and where he wants us to be when we've got the ball.
"We've got the core and got the clean sheet and now we want to take that further up the pitch and get the goals and I think that will come."
WBA midfielder Craig Gardner speaks about Saturday's FA Cup Fourth Round tie at Birmingham City
