England pair Dylan Hartley and Courtney Lawes are doubts for the November Tests after suffering knee injuries in Northampton’s defeat by Saracens.
Both players were forced off before half-time and Saints director of rugby Jim Mallinder said they would be assessed by England staff on Sunday.
Hartley’s injury in particular is a major problem for England head coach Stuart Lancaster. The only other hooker in the senior squad is Leicester’s Tom Youngs. Bath’s Rob Webber and Harlequins’ Joe Gray are injured while another Bath hooker, Lee Mears, has retired from international rugby.
It is likely that London Irish’s David Paice, who was in the most recent Saxons squad, will be called up to the senior squads for the Tests against Fiji, Australia, South Africa and New Zealand.
“They’ve done something, but we will know a lot more later,” said Mallinder.
“They are the sort of characters that if they had just got a knock they wouldn’t have come off.”
Lock Lawes had a long lay-off last season because of an injury to his right knee but this time the problem was with his left knee.
Lancaster will be hoping they both recover for Northampton’s clash against Leicester at Welford Road next Saturday.