England coach Stuart Lancaster has revealed that Alex Corbisiero is "unlikely" to be fit for Saturday's match against Australia at Twickenham Stadium due to a knee injury.
The 25-year-old, who plays his club rugby for Northampton Saints, has been struggling with the problem for the last few weeks.
"He's unlikely to make the Australia game but we're hopeful that off-field work and rehab will put him in contention for the Argentina game (the following week)," Lancaster told Sky Sports News.
Corbisiero has won 18 caps for England since making his debut in 2011.