Blake Shinn is determined to guide topweight Happy Clapper to his first Group One victory in the Epsom Handicap as a tribute to a trainer who has lightened the burden for jockeys.

Shinn highlighted Pat Webster's work as a mentor for young riders through Racing NSW when he declared his desire to win aboard the favourite in Saturday's $1 million mile at Randwick.

"I really hope for Pat Webster's sake he can get the Group One," Shinn said.

"He's done an amazing job with the horse and he does a lot for the industry with young kids and what not.

"Pat deserves his chance in the limelight and some really good recognition."

Happy Clapper is looking to become the third horse this century to win the Epsom carrying 57kg, joining Racing To Win (2006) and Winx (2015).

Shinn believes the weight is no issue and was pleased with Happy Clapper's barrier draw of four in the 14-horse field.

"He's in well with the weights," he said.

"He's going to get every chance. He's got the best form lines of any horse going in. I'm very confident."

Shinn said the barrier would allow him to get Happy Clapper into a perfect position.

"There's going to be a lot of pressure but I've just got to put him in a nice comfortable rhythm," he said.

"He'll be in a position where I want him to be."

Happy Clapper, who has amassed more than $2.4 million over his 27-start career, also has an affinity with the track and the distance with his worst result over the mile at Randwick when fourth in last year's Epsom.

He was runner-up to Winx in the 2016 Doncaster and followed It's Somewhat home in this autumn's edition.

Happy Clapper also lost out to Winx in the George Main Stakes on September 16, but it was an effort that added to Shinn's confidence.

"He gave a Winx a real test. I think it was a real career best performance," he said.

Happy Clapper firmed from $4 to $3 on Tuesday while Egg Tart, one of five runners for Sydney's premier trainer Chris Waller, eased from $4.80 to $5.

The mare needs a veterinary clearance to run after suffering an eye injury.

She will undergo a second inspection on Wednesday after failing to satisfy Racing NSW vet Craig Suann on Tuesday.