David Pocock is fighting an uphill battle to be declared fit to play in the Wallabies' World Cup semifinal on Sunday.
The hugely influential back rower, on whose shoulders — some believe — rests Australia's World Cup hopes, completed some running at training on Tuesday but was confined to a stationary bike on Wednesday on the advice of medical staff.
The calf strain he picked up against Wales in the pool stages was given a two-week recovery time frame, giving Wallabies fans hope the prolific turnover merchant would be fit and able for this weekend's semi-final clash with Argentina at Twickenham.
Michael Cheika will hold out until Friday to make a call on Pocock's availability, giving the Brumbies flanker one last training session to prove his fitness.
The Wallabies coach remains upbeat about his star back rower's chances, but early optimism appeared to be fading mid-week.
Pocock is not the only starting player on whom the Wallabies are sweating. Fullback Israel Folau (ankle) and prop Scott Sio (elbow) both failed to complete full training on Wednesday.
Folau made it through 10 minutes of training before coming off to ice his ankle, while Sio completed a restricted session before hopping into an ice bath.
The Brumbies prop is the least likely to be available, after taking a heavy knock on his elbow during a scrum in the Wallabies' 35-34 quarter final win against Scotland on Sunday.
Cheika will name his 23-man squad on Friday, local time, with Kurtley Beale the clear choice to replace Folau, after a performance against Scotland that drew strong praise from the coach.
"I thought Kurtley Beale was outstanding at fullback," Cheika said on Monday. "Even the decision he made at the end, when we got the ball back, and he kicked it long into the corner there — that's not a decision he would've made a couple of years ago.
"He thought about what the team strategy could be there, put a great kick in there and gave us some field position to try and put some pressure on the opponent. He considered the conditions and everything like that. I thought he had a great game."
James Slipper will come in to the front row at loosehead prop in place of Sio, while the Wallabies insist they are not flying in back-up for Sio, a vote of confidence in his recovery. Greg Holmes and Toby Smith would be called upon instead. Cheika is likely to opt once again for Ben McCalman in the back row if Pocock is ruled out. McCalman was a standout against Wales in the group stages and lived up to his workhorse reputation against the Scots.
The Western Force No 8 made a try-saving tackle on Welsh centre George North during the 10 minutes the Wallabies were down to 13 men. The effort prompted Force coach Michael Foley to compare it to George Gregan's game-saving tackle on Jeff Wilson in the famous 1994 Bledisloe Cup test.
Foley said McCalman was the silver lining to the Wallabies injury cloud should Pocock not pass muster. "Irrespective of how difficult a moment it might be he'll find a way to do something that makes a difference," he said.
"That moment against Wales wasn't a one off, it was indicative of his quality and what you get from him every time that he is selected."
