"UPBEAT" Queensland fullback Billy Slater will be his own judge and jury come decision time on whether he is fit enough to play in next Wednesday's Origin decider at Suncorp Stadium.
The Storm phenomenon is racing time to recover from the posterior cruciate ligament strain he sustained in Origin II, with Maroons coach Mal Meninga giving him until Saturday to declare his fitness.
That decision would be Slater's alone, Meninga said yesterday at Queensland's Coolum training base after announcing the Maroons had decided on an initial 20-man squad for the decider.
The Queensland coach also revealed he would be unconcerned if the star custodian came into camp at the last minute, saying Slater knew the team's play book so well that he did not have to train with the side.
Slater is still in Melbourne being assessed by the Storm's medical staff.
Meninga said the lethal ball magnet had a run on Monday morning and was "very upbeat about the situation".
"We expect to see him when he's right to go," Meninga said. "At this stage we're very hopeful (but) uncertain … if Billy tells me he's right to go, he's right to go."
Queensland captain Cameron Smith cautioned against being too optimistic about his Storm teammate's playing chances, saying there was "a big difference between running in a straight line on a training paddock and getting out in State of Origin".
Broncos captain Sam Thaiday, who missed Origin II with a shoulder injury, Brisbane lock Ben Te'o, Melbourne centre Dane Nielsen and Cowboys fullback Matt Bowen are the additions to the squad after the loss in game two in Sydney.
Maroons lock Ashley Harrison has been ruled out with a broken toe and Bronco Corey Parker is tipped to take his spot.
If Slater is sidelined, it has been widely speculated that Greg Inglis will move from centre to fullback and Nielsen will play centre. But Meninga said Bowen was playing "terrific" football.
The Queensland coach added more intrigue to the Maroons' possible line-up by saying he might use a back and three forwards on the interchange bench instead of four forwards.
Bowen could end up playing regardless of Slater's availability.
Meninga conceded there was a chance Bribie Island product Matt Gillett, who started on the bench in the first two games, could be a selection casualty.