The biggest win of Allergic's career may have cost him a shot at a Group One race.

Sent out the $2.05 favourite, Allergic held out the veteran stayer Junoob ($3.10) by a neck in Saturday's Group Three Colin Stephen Quality at Rosehill.

Trainer John O'Shea said a tough run on a dry Rosehill track might force him to abandon plans for the Group One Metropolitan at Rosehill next Saturday.

O'Shea said the Metropolitan had been the horse's target but he expected Allergic would not recover in time to handle a quick back-up after running on a firm surface.

"it is disappointing because we had ambitions of running him next Saturday but he has had a hard run on ground like that," O'Shea said.

"We will get him home, freshen him up and see how he goes.

"Hopefully that will help him."

Allergic is an $8 chance for the Metropolitan following his first Group win.

Jockey James McDonald said the gelding could run in the Metropolitan provided there was give in the surface.

"He was alright but I still reckon the track was a bit firm for him because I have felt him let down better than that," McDonald said.

Allergic's stablemate Alegria ($5) finished third after jockey Tim Clark made a mid-race move, rounding his four rivals and sweeping to the lead at the 800m.

O'Shea nominated the Listed City Tattersalls Club Cup at Randwick on October 15 as Alegria's next assignment.