NSW look set to keep Queensland guessing over the availability of Robbie Farah for Origin III until an hour before kick-off as the Tigers skipper races the clock to be fit for the decider.

Farah has already displayed plenty of courage so far this series after playing on with a busted AC joint in his shoulder in game one.

Around-the-clock treatment from NSW medic - his brother Eddie - allowed Farah to play in the Blues' game two victory at the MCG with the help of a pain-killing injection.

But a broken hand suffered in the Tigers' round 16 loss to the Panthers that required surgery less than a week before game three put him at long odds to be fit for the decider.

Farah was set to train with NSW on Tuesday and skipper Paul Gallen said the decision on his fitness would ultimately rest with his vice-captain.

"[We'll] Probably wait until an hour before kick-off, I think," Gallen said.

"Robbie's the only one who knows at the end of the day. We've seen him passing, kicking and carrying on, so we'll see.

"Obviously Laurie's going to give him every chance to get out there and he probably deserves that. Robbie won't give up that's for sure."

Gallen gave little away addressing the media on Tuesday but put his faith in Farah's shadow Michael Ennis should his vice-captain rule himself out.

Ennis played for NSW through their darkest days during Queensland's eight-year reign of Origin supremacy before being usurped by Farah for the 2012 series.

His six losses in 10 games for the Blues don't look all that flattering but Gallen is confident his Sharks teammate is up to the task.

"He's been great since day one," Gallen said.

"He hasn't been shy, he's really stepped up and been somewhat of a leader around the side, as he is in all sides.

"He's run most of the sessions in and out with Robbie.

"We've got a game plan in place and we could really throw anyone in there. If we stick to the game plan we'll be fine. He knows the game plan inside out already, he's a professional, everyone likes him ... a few of the boys were a bit wary of him at the start but even big Woodsy came up to me and said 'he's not a bad bloke', so he'll be fine."

Farah's absence would be a big blow for the Blues but Gallen said Ennis' status as one of the game's great nigglers could prove a bonus in what's sure to be a fiery encounter.

"I saw Matt Scott the other day already complaining about it, so he's already under their skin," Gallen said.

"He's just a competitor and he's got a bit of niggle in him ... more talk than niggle but he'll be great. If he gets out there and gets his opportunity, he'll make the most of it."