Bratich was the first Australian woman to win a medal at the karate world titles in more than a decade with a bronze in 2006, but hopes to go one better next year at the championships in Serbia.
While other wives and girlfriends have spent the time carrying shopping and baby bags.
Bratich has convinced Johnson that he can spend is time more fruitfully by holding a kick bag.
"This is the first time training with Mitch. The problem is that when we do it he seems to want to fight, he gets right into it," Bratich said.
Bratich is aiming to compete in the Australian Open titles in April.