Australia's Mitchell Starc bowls during play on the fifth day of the fourth Ashes cricket Test match between England and Australia at Old Trafford in Manchester, north-west England on September 8, 2019. (Photo by Oli SCARFF / AFP) / RESTRICTED TO EDITORIAL USE. NO ASSOCIATION WITH DIRECT COMPETITOR OF SPONSOR, PARTNER, OR SUPPLIER OF THE ECB (Photo credit should read OLI SCARFF/AFP/Getty Images)

Mitchell Starc has returned bigger, faster and stronger.

The Aussie left-armer has added five kilograms of muscle during the off-season as he looks to maintain his status as the game's fastest bowler.

Mitchell Starc says his off-season in the gym and modified bowling action could see him hit the magical 100mph mark.

During the COVID-19 layoff, Starc trained with his NSW teammates and says the break allowed him to rest after an 11-month stretch of continuous cricket.

"At the end of summers, I've been down to 87kg at my lowest and I'm at 93kg at the moment which is where I want to be at," Starc told

"I've started summers around that 90-91kg mark so I'm in a good place now, feeling really strong.

"It's been a good amount of time in the gym and now I'm back bowling and running and have enjoyed the time at home to be able to do that and rest the aches and pains of bowling through an 11-month tour like the other boys have as well.

"Perhaps that extra time in the gym and extra time off I might be able to push the limits again.

"At the start of the (2019-20) summer and after that UK tour, I very much got in that line and length (and) consistency mindset that the whole (fast bowling) group were about through the Ashes.

"That's not to say that's not important, but I think I've found a happy medium with this little tweak to still have that better consistency but still have my pace."