McCormack joined Melbourne City in Australia from Villa in the Championship in England in late September.
The 31-year-old striker made his debut for City last Friday against Brisbane Roar in the A-League.
The former Leeds United and Fulham star played for 82 minutes, as Warren Joyce’s side won 2-0 at the AAMI Park.
The performance of McCormack was encouraging but not great, and the Scotland international striker has said that he will eventually come good once he is fully match fit.
“It was good,” McCormack told Melbourne City’s official website. “That was my first start since March and I think it was 80 minutes under my belt. It was a bit rusty but it can only get better.
“Fitness wise was fine, it was just more sharpness that I’m going to be working on in the coming weeks to get back to where I feel I need to be.
“It’s just all about training every day, and to be fair, the manager demands it and the boys are doing it.
“I think if you work hard and concentrate on playing well, hopefully the chances will start to be created and I back myself if I get chances to score goals.”
McCormack joined Villa from Fulham in the summer of 2016 for a transfer fee reported by BBC Sport to be worth £12 million.
Much was expected of the former Cardiff City star when he arrived at Villa Park, but the striker failed to make an impact and after a loan spell at Nottingham Forest during the second half of last season, he joined Melbourne City last month.