Australian halfback Johnathan Thurston passed a fitness test on his injured ankle Friday morning and will play in Friday night's Centenary Test against New Zealand at the SCG.
A team spokesman said Thurston had performed "better than expected" when he ran on Friday morning in front of team medical staff.
"Unless it swells up dramatically this afternoon he should be right to take his place," the spokesman said.
Melbourne halfback Cooper Cronk remains on standby for Thurston, who rolled his ankle at training on Thursday and partially tore ligaments.
The news is a major boost for the Kangaroos, who lost skipper and Thurston's halves partner Darren Lockyer on Sunday.
Australia would have gone into Friday night's Test without a full training session with Cronk at No.7 after he only arrived in camp on Thursday night.