It's been almost a year since the six-year-old's last win, the Group 3 JRA Plate on a heavy track back in April, and with James McDonald back on board for the first time since that win the trainer senses the Listed $200,000 Parramatta Cup (2000m) is an opportunity.
"The jockey riding him on Saturday seems to have an affiliation with him,'' John O'Shea said.
"We've been happy with him all prep, he ran very well last time and up to stable expectations and he hasn't taken a step back."
Diamil, $3.60 with TAB on Wednesday, faced an impossible task mathematically when he chased Amor Victorious home into third over a mile at Randwick two weeks ago under 61kg.
He clocked a race best final 600m of 33.67, more than two lengths faster than anything else, and an 11.66 final 200m (Punter's Intelligence) and will drop 3kg into the Parramatta Cup.
O'Shea said in an ideal world the track will stay in the soft range and McDonald will be able to make good use of an inside barrier.
"We can't fault him. He didn't get out of the gates real good (first-up) so we'd really like him to jump and take a spot if he could,'' he said.
"We may try him over a bit further this prep we'll just see what he brings.
"We were happy with him last time in, he was just getting hard tracks and wide barriers.
"A lot of the races he ran in he wasn't much of a winning chance until he got to the Coongy and he ran very well."
Stroke Of Luck begins what O'Shea plans to be a conservative autumn campaign in the Parramatta Cup despite the outside barrier as he looks to later in the year for his major aim.
The gelding was placed in the Queensland Derby last year and enjoyed a successful spring which ended in victory in the $300,000 The Beauford (2300m) at Newcastle.
"He needs to get started because he has a few things on his agenda,'' O'Shea said.
"He came back into the stable in great order, his work has been really good and the trials excellent.
"He's about having a relatively light autumn with a view to hopefully getting him to Melbourne at the end of the year."
There'll be plenty of attention on the return of Café Millennium in the Group 2 $400,000 Precise Air Hobartville Stakes (1400m) and O'Shea is far from giving up on the hulking colt.
He started his career in a blaze of glory but his best effort since then was a fourth in the Group 3 Ming Dynasty over the same course back in the spring.
After winning his latest trial, the trainer hopes Café Millennium can start to live up to his promise this year.
"He's finally grown into his big frame, we just need him to execute out of the gates a bit better,'' he said.
"Nash (Rawiller) did give him a good education at his last trial and he raced accordingly. If we can get all that sorted out that'd be good.
"We're happy with him, he put in a lovely piece of work and hopefully we can get continuity to his program to get him out to 10 furlongs this time which would appear to be the right distance for him."
John O'Shea on Premise (race 6): "We set her up to go to the Matriarch, she had a really good lead up race in Sydney three weeks out then got to Melbourne and didn't acclimatise well or settle well and ran accordingly. We got her back at the farm and she trialled up really well the other day. I wouldn't think she's a winning chance on Saturday but I think she will run well and go to the Aspiration. She's come on and she loves getting her toe in the ground so I expect her to give a good account."
