England are assessing the fitness of Ellis Genge as they ramp up preparations for their Guinness Six Nations title clash with Wales on Saturday week.
Genge pulled out of training on day two of the squad's London camp because of an ankle injury to place a cloud over Eddie Jones' options at loosehead prop.
Mako Vunipola, England's first choice in the position, is sidelined for 10 weeks because of his own ankle problem sustained against France.
Genge and Ben Moon are battling for the number one jersey in Vunipola's absence, leaving the Championship's form team anxious to avoid any further setbacks.
"Ellis Genge in training today (Thursday) reported a sore ankle so he was withdrawn from training," forwards coach Steve Borthwick said.
"He reported the ankle so we said 'right stop training, we won't push that'. We don't think there will be any major consequences. It's ongoing and it was the right decision to ensure he didn't finish training."
Vunipola was the Six Nations' outstanding operator until he hobbled off in the second half against France, making more tackles and carries than any other player during his two matches.
"Mako's play has been exceptional. He's grown and grown over the years. He has a presence," Borthwick said.
"He doesn't talk an awful lot, but when he does people listen. They pay attention. It's all about presence and he backs that up on the field.
"He has enormous respect from his team-mates. It's disappointing because he's a very good player.
"But we've also got some very good loosehead props in Ben Moon – look at the way he played in November – and Genge, who is also an excellent player."
England have yet to rule Maro Itoje out of the eagerly-awaited clash with Warren Gatland's men as the British and Irish Lions lock recovers from a knee injury.
"Maro's progressing well each day. He's working exceptionally hard as you'd expect from him," Borthwick said.
"He's doing everything possible he can to recover as quickly as possible. He's on track to be back on the field in the latter part of the tournament. He's healing fast and we'll looking at it on a day by day basis."
