Manu Tuilagi has withdrawn from England's two-day training camp after suffering a knee injury playing for Leicester Tigers on New Year's Day.
The 25-year-old centre was forced off inside the opening eight minutes of Sunday's 16-12 defeat by Saracens and is expected to find out the full extent of the injury by Tuesday.
"It looks like a knock and a bit of swelling, but it is too early to say," Tigers director of rugby Richard Cockerill told BBC Sport.
"He's a bit cheesed off as you can imagine. He has hurt the outside of his right knee.
"His groin is good, his knee is a bit sore. We will assess it over the next 48 hours and we will deal with whatever comes."
Bath wing Semesa Rokoduguni will replace Tuilagi when the 33-man squad meets in Brighton on Monday, with the start of the Six Nations a month away.
