A knee infection is the latest in a series of setbacks to take a toll on the brief career of Of The Brave.

The Mark Riley-trained colt was due to resume in the Vain Stakes at Caulfield on Saturday but is undergoing treatment for his latest ailment.

Of The Brave galloped between races at Sandown last Wednesday which had the trainer and jockey Stephen Baster looking forward to the upcoming spring.

But the colt developed an infection over the weekend in the same knee which put him on the sidelines after a debut win at Caulfield last October.

"It's the same knee but it's nothing to do with that," Riley said.

Of The Brave returned in the autumn to defeat Pride Of Dubai in a Blue Diamond Prelude on February 14 before finishing down the track in the Blue Diamond two weeks later.

After his fading 12th in the Blue Diamond, Of The Brave was diagnosed with inflammation of the airway, which Riley said after his Sandown gallop last week would not hamper the colt's spring ambitions.

Riley said his vets are looking after the colt and hopefully he's not sidelined for too long.

"He's not lame and he's walking around his box fine," Riley said.

"Apart from the fact we know the swelling is there and he's got an infection there, you wouldn't know anything is wrong with him."

Riley has not dismissed getting Of The Brave back for the spring with the Group One Coolmore Stakes at Flemington on Derby day his main aim.

"The spring is not finished for him at this stage," he said.

"It's not the end of the world if he misses the spring just as long as we can get him back to the races.

"Everything has gone wrong with him, we now just need something to go right for him."