The midfielder has begun training after a second cruciate knee ligament injury sidelined him back in August.
"There have been long days at Bodymoor Heath and people don't see that," Gardner told the Express & Star. "You must put lots of work in, but I've been brought up in that background - working hard and keeping my feet on the floor.
"It's just about how I feel, taking it steady and then building it up. You train three times a week and then four times and then full training.
"I just have to see how I feel - I know my body. This knee feels brilliant so hopefully I can take it steady and get back in there."