The Caulfield Stakes has lost one of its main contenders in Manighar but that hasn't changed anything for Glen Boss who rides the favourite Ocean Park.

Boss expects Ocean Park to keep his impressive spring form going at Caulfield on Saturday to set up a mouth-watering $3 million Cox Plate two weeks later.

Manighar was ruled out of the Group One Caulfield Stakes (2000m) and the remainder of the spring on Thursday with a knee injury, prompting Ocean Park to be tightened from $2.20 to $1.55 for the weight-for-age race.

"Nothing really changes as far as my thought processes go," Boss said.

"I've still got to go out there and give him a good ride and get the job done.

"I probably thought I had them covered anyway."

Ocean Park is on the second line of betting for the Cox Plate, sandwiched between Gai Waterhouse's two stars Pierro and More Joyous who will also be in action in separate races at Caulfield.

Boss believes this year's Cox Plate is shaping as "a real cracker" and is looking forward to the challenge.

"On Saturday there is More Joyous going around (in the Toorak), Pierro (in the Caulfield Guineas) and him (Ocean Park)," Boss said.

"They are the three favourites going to the Cox Plate and they are all running on the same day. I'd really like to see all three horses stand up and stamp themselves on Saturday. I'm sure my horse will hold up his end of the bargain."

Boss first rode Ocean Park to second in the Rosehill Guineas in March and his second ride on the Gary Hennessy-trained entire reaped a Group One win in the Underwood Stakes (1800m) at Caulfield two weeks ago.

He said the son of Thorn Park was "a real athlete" with the turn of foot needed in big weight-for-age races.

"You could see what he did the other day, that was no fluke," Boss said.

"He's always been a nice horse and he's developed into a nice horse. I think he should be in for a very good preparation.

"I've ridden him in work since his last start win and he feels great."

The injury to Manighar leaves a field of seven for the Caulfield Stakes with the Stephen Farley-trained Sincero second favourite.

Sincero is also being aimed at the Cox Plate.