Maro Itoje is to miss at least a chunk of the Guinness Six Nations due to the knee injury sustained against Ireland on Saturday.
Press Association Sport understands that a scan has revealed Itoje suffered a grade two medial ligament tear that usually requires two to four weeks of rehabilitation.
The prognosis means that the British and Irish Lions lock could be available for the finale to the tournament against Scotland on 16 March - and potentially earlier.
Itoje was on Monday afternoon due to see a specialist to be given a clearer picture of when England can expect him back.
Losing their second row talisman for Sunday's clash with France and almost certainly Wales a fortnight later is a substantial blow to Eddie Jones' men.
Itoje is crucial figure in England's pack and his power and work rate were key in subduing champions Ireland at the Aviva Stadium.
Either Courtney Lawes or Joe Launchbury will slot into the starting XV in his absence, partnering George Kruis in the second row.
Lawes made a forceful second-half appearance in Dublin, but, while Launchbury was excluded from the matchday 23, England may want his bulk on from the start.
Meanwhile, Wasps have vented frustrations in confirming England starter Elliot Daly will leave the Coventry club at the end of the season, with Saracens his expected destination.
Rugby director Dai Young refused to hide his disappointment in admitting Daly has used a release clause in his contract to leave despite a year remaining on his Wasps contract.
British and Irish Lions flier Daly's departure will prove a significant blow to Wasps, who will also lose England number eight Nathan Hughes to Bristol this summer.
Wasps have already secured the prize signature of All Blacks centre Malakai Fekitoa for next season, but will also lose the influential South Africa full-back Willie Le Roux in the summer.
"Elliot triggered a release clause in his contract and despite our best efforts to keep him at the club, unfortunately he has decided to move onto pastures new for the 2019/20 season," said Wasps rugby director Young.
"We are really disappointed to lose Elliot, we brought him through the ranks from his teenage years and have seen him flourish into an established England international and also a British and Irish Lion.
"He has really developed his all-round game in the black and gold, having been a tremendous performer for us over the years and I am sure he will continue to give his all for the club until the end of the season."
