The 2021 All Star Mile winner tailed off last in a 1400-metre handicap at Rosehill - his first race in almost 15 months following a serious tendon injury.

A Racing NSW veterinary examination of Mugatoo revealed no abnormalities but Lees reported to stewards that the eight-year-old gelding had blood in one nostril when he returned to the stable. Lees told stewards he would report back about Mugatoo's racing future.

Under the rules of racing, Mugatoo will need to have a satisfactory gallop of at least 1000m in the presence of a steward before he is allowed to race again.

The Irish-bred gelding had already overcome a throat operation in the UK to become one of Lees' best earners, winning $3.4 million in just 16 Australian starts, despite never achieving a group 1 victory.

His win in the All Star Mile earned a cheque of $2.25 million, second only for Lees behind Lucia Valentina's Queen Elizabeth Stakes prizemoney of $2.4 million.

He delivered Lees a prized first Newcastle Cup in 2020 and was also a close second in the group 1 Metropolitan and a luckless fourth in the Cox Plate that year.

Mugatoo had four trials, the first in May, to prepare for his comeback race on Saturday, where he was carrying 62 kilograms.

Also on Saturday, Hellbent filly Hellavadancer led all the way to win a 1500m benchmark 72 handicap for three-year-olds at Eagle Farm. Sent out a $2 favourite, Hellavadancer was taken to the lead by Jim Byrne and she kicked clear to win by three and a half lengths.