Manu Tuilagi remains in surprise contention for Saturday's climax to the autumn series at Twickenham in an unexpected twist over the England centre's fitness.
Tuilagi has been retained in a squad of 26 players to make final preparations for the visit of Australia despite being described by Eddie Jones as "very doubtful" to participate in the Cook Cup clash.
The Leicester centre was due to make his first international appearance since 2016 in the opening QBE International against South Africa only to be withdrawn from the bench because of a groin strain sustained in training and has not played since.
England declared last week that the Wallabies showdown was being targeted for his return, but on Monday Jones stated that he is only "99.9 per cent and we'll wait until he's 100 per cent".
For the last four years Tuilagi's career has been blighted by serious groin, knee, pectoral and hamstring injuries, but he could yet feature among the matchday 23 when Jones names his team on Thursday.
Chris Ashton will definitely miss the Australia showdown, however, after being stricken by a calf problem.
He will be limited to three appearances this month due to the injury sustained in the 35-15 victory over Japan, a scan confirming that he will be sidelined for a fortnight.
The 31-year-old became available for England once more when he left Toulon for Sale over the summer and Jones immediately selected him in his squad for the autumn.
When Tuilagi was prevented from playing South Africa, Ashton was cleared to win his 40th cap and first in over four years.
"Chris Ashton was hurt in the game on Saturday," forwards coach Steve Borthwick said.
"He's been scanned and investigated and unfortunately the injury means he will be out for a couple of weeks. He'll leave camp today (Tuesday).
"Chris is a fantastic player who knows his way to the try-line. He's been great around the squad the last few weeks. It's very disappointing he's out."
Ashton fell out of favour under Stuart Lancaster and then Jones, whose opportunities to pick the dual code international were restricted by a succession of bans.
He made only one appearance for Sale this season due to a seven-week suspension incurred for a tip-tackle before being picked by England.
Jonny May and Jack Nowell are set to be restored to the wings for the first time since the series opener against South Africa, but Bath powerhouse Joe Cokanasiga is a fringe contender to start.
Cokanasiga produced a promising debut against Japan, using his 6'4" and 18 stones frame to good effect to score the decisive try and make a number of dents on the Brave Blossoms line.
However, having just turned 21 years old the Wallabies might be deemed too big a hurdle to face.
"Joe did really well. He's got massive potential and is really eager to learn and hungry to learn," Borthwick said.
"Physically he's got some great attributes and attitude wise he wants to be the best he can be. He's a young guy who has a lot of potential."
