The importance of having two chances in Group One races on one of Australia's biggest days at Caulfield is not lost on emerging trainer and former champion apprentice jockey Nick Ryan.

Ryan is chasing the first Group One win of his career on Saturday with Express Pass set for the $2 million Caulfield Guineas and Mahamedeis in the Toorak Handicap.

"It's probably my biggest day as a trainer or jockey, in either career," Ryan said.

"If one of them was to win, or even running a place it would be a big thrill.

"But we're there to win.

'It's been a real long-range plan to have these two here on this day and they're both really well.

"Let's hope everything works out."

Ryan achieved a lot as a jockey before weight forced him to hang up the saddle.

He remains the most recent apprentice to win the Melbourne jockeys' premiership in 2004/05. But a Group One eluded him.

He came closest when beaten a short half-head on champion filly Alinghi in the 2004 Empire Rose Stakes at Flemington.

Having taken up training about five years ago, Mahamedeis' fifth in last year's Queensland Derby has been his lone Group One runner.

The winner of seven of his 26 starts and runner-up to Homesman in the weight-for-age Group Two Feehan Stakes over 1600m two starts ago, Mahamedeis is $12 in the Toorak (1600m) from barrier one.

The Guineas (1600m) has been the target for Express Pass since he ran home strongly for third on debut at Caulfield in the Listed Redoute's Choice Stakes (1200m) in May.

The colt is having his fifth start on Saturday.

He was placed in the Group Two Danehill Stakes two starts ago but things did not go to plan when he finished ninth in the Guineas Prelude (1400m) after jockey Ben Melham had to take evasive action near the 1000m when Jamie Kah fell from Yourdeel.

"It was not the ideal lead-up run with that mishap," Ryan said.

"That horse fell in front of him and he got speared off the track."

But Ryan was still taken by the sectional times the colt ran and said he was entitled to finish further back than he did.

"He's definitely got a motor. He's got the winkers on from barrier eight. If he can get a good run and produce the sectionals he can reel off, he's got to be a live chance," Ryan said.

"Possibly the only query is whether he's going to run the mile. We didn't get the right guide the other day, but he has drawn well and this has been the target race for a long time.

"He's given me every indication he will run the distance but we'll find out on Saturday."