Henry Slade is a doubt for the climax to England's Guinness Six Nations campaign against Ireland on Saturday because of a lower leg problem.
Slade sustained the unspecified injury in training on Monday and a decision on his availability for the round-five clash at the Aviva Stadium is expected on Tuesday.
The strides taken by England in attack during the last two games have brought out the best in the Exeter Chiefs man, who has forged an improving centre partnership with Owen Farrell.
England have called Harlequins back Joe Marchant into camp as cover for Slade, but if he fails to recover in time then Ollie Lawrence or Paolo Odogwu are most likely to benefit by filling the vacancy in midfield.
"The way Henry works off the ball is second to none. The way he puts himself in a position to attack and defend is brilliant," said England skills coach Ed Robinson.
"The way he sprints to chase kicks is phenomenal and that is a massive part of his game. He's a big driver in that for us.
"Joe is a fantastic player because of the way he works on and off the ball. His skill set on the ball and the way he supports are both excellent."
