England scrum-half Dan Robson has been ruled out of action after suffering with blood clots, his club Wasps confirmed on Saturday.
Robson, who came off the bench to score his first test try in England's 57-14 Six Nations thrashing of Italy last weekend, was ruled out of Saturday's clash with Scotland due to illness.
Wasps announced that it is "too early" to confirm when Robson will return and he could potentially miss the rest of the season.
"Wasps can confirm that Dan Robson suffered blood clots which arose spontaneously earlier this week and is being evaluated and treated by specialists at the moment," the club said in a statement. "At this stage it is too early to give a return-to-play date."
Blood clots form in veins or arteries and Robson reportedly complained of leg pain on Tuesday before being taken for immediate medical treatment.
England could claim the Six Nations title on Saturday but they will need Ireland to beat Wales in the earlier kickoff at the Principality Stadium.
Information from Reuters was used in this report.