Peter Moody's stayer Manighar has been ruled out for the entire spring after picking up a knee injury.
Manighar, who was set to start in Saturday's Caulfield Stakes and the Group 1 Cox Plate in a fortnight, has been sent straight to the paddock and will not be seen again this year.
The extent of Manighar's injury is unknown, but Moody said the seven-year-old would require an operation and will be spelled.
Manighar's absence for the Caulfield Stakes could be Ocean Park's gain, with the Kiwi galloper shortening even further after the news.
Ocean Park is a short-priced favourite for the Caulfield Stakes, with Memsie Stakes winner Sincero the only other horse under double-figure odds in the small field of seven.
Big race jockey Glen Boss is in no doubt Ocean Park is not only the horse to beat in Saturday's Group 1 $400,000 Caulfield Stakes (2000m) but also in Australia's weight-for-age championship - the $3 million Cox Plate at Moonee Valley in a fortnight.
Ocean Park - runner-up in the Rosehill Guineas as a three-year-old in the autumn - has returned in sensational style this spring winning both his starts so far at Group 1 level as a four-year-old.
His most recent win was a slashing second-up performance in the Underwood Stakes at Caulfield over 1800 metres three weeks ago and this time around he meets just six rivals - most of whom finished unplaced behind him in the Underwood.
Boss said his mount had improved since its last-start victory and that he can't see any of the beaten brigade from the Underwood turning the tables on Saturday.
"He has done nothing but thrive," Boss told Melbourne racing radio station ''RSN'' when asked if Ocean Park had improved since his Underwood Stakes win.
"He just continues to improve and as soon as you get on him you feel as if he is a great horse."
While Gai Waterhouse's unbeaten three-year-old colt Pierro is the hot favourite for the Cox Plate - as well as for Saturday's feature race in the $1 million Caulfield Guineas for three-year-olds over 1600 metres - Boss says Ocean Park is definitely the horse he wants to be on come Cox Plate day.
"No doubt," he said when asked if Ocean Park was good enough to win the Cox Plate."He has two starts this campaign and won both at Group 1 level and I am just so looking forward to being back on him on Saturday (in the Caulfield Stakes)."