"I won't write him off, he is a bloke who is passionate about playing for NSW, we will give him every chance and see what happens.
"Hopefully he will get through tomorrow's session under some more intense work.
(But) we won't definitely make a decision tomorrow.
"For us it is about giving Robbie the best chance to play, he is a big part of our team."
After their two major pre-Origin III hitouts on Saturday and Sunday at their Coffs Harbour base, the Blues flew to Brisbane on Sunday afternoon. They had a day off on Monday, ahead of their final training session in the captain's run at Suncorp Stadium on Tuesday.
Michael Ennis will take Farah's spot in the Blues line-up if the Wests Tigers skipper is ruled out.
However Farah's availability might not be confirmed until an hour before kick-off, when the teams are named.
The NSW judiciary loophole that has opened up Ennis' availability, after his one-match suspension, closes at the conclusion of the final round 17 match between Parramatta and Wests Tigers on Monday night.
Daley said the issue of Farah's fitness hadn't been a distraction in the lead-up to game three.
"Robbie is the type of guy who puts the team before himself," Daley said.
"He is very committed to NSW, he has been a big part of our team, if he does play, we know he will play well for us on a limited preparation."
Captain Paul Gallen is also an injury worry for the Blues as he battles a rib complaint sustained in Origin II.
Daley said Gallen also picked up an undisclosed injury in training on Sunday, but said the Cronulla skipper wasn't in doubt for the decider.
-AAP