Ozzmosis gave trainer Bjorn Baker and jockey Rachel King the biggest wins of their careers in the spring, taking out the stallion-making Group 1 Coolmore Stud Stakes (1200m) and the colt's next challenge is tackling the older horses.

The son of Zoustar will likely stay in Sydney for the autumn with two Group 1 sprints identified by Baker as targets, one a handicap and one at weight-for-age.

"We are going to The Galaxy then the TJ Smith Stakes. There is nowhere to hide now," Baker said.

"He is going great … he has definitely gotten bigger and stronger."

"Even with the 10 days we were away at the Magic Millions, I've noticed how much he has come on, he's thriving."

Meanwhile another stable Group 1 winner is back in work with Tancred Stakes hero Arapaho trialling on Monday morning at Randwick after missing the majority of the spring with a virus.

Arapaho had just one run in the spring, finishing 10th in the 7 Stakes (1600m) before being spelled but Baker is happy with how the stayer is going having finished fifth in his trial behind Queen Of The Ball over 850m.

"He's great, I couldn't be happier with him," Baker said.

"He's definitely bigger and stronger after having a soft spring."

"He will be aimed at the Tancred Stakes."

Rachel King, who landed a Group 2 winner in Japan on Sunday, rode both Ozzmosis and Arapaho to their respective Group 1 wins and should be back for the Sydney autumn, with her short-term JRA license set to expire on March 5.

Baker also confirmed that Group 1 winner Overpass will again head west for his defence of The Quokka on April 20 and will tackle the race fresh, as he did last year.