England are optimistic Ellis Genge will not join Mako Vunipola on the sidelines after he was unable to complete training on Thursday due to an ankle injury. 

The Six Nations leaders suffered a big blow this week when Vunipola was ruled out of the rest of the tournament after suffering ankle ligament damage in the victory over France last Sunday. 

Fellow prop Genge, among the contenders to replace Vunipola, cut short a training session after reporting pain in his ankle. 

However, England forwards coach Steve Borthwick played down concerns over the fitness of the Leicester Tigers front-rower ahead of the showdown with Wales on February 23. 

"Ellis Genge in training today reported a sore ankle so he was withdrawn from training," Borthwick said.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 outstanding in England's wins over Ireland and France before suffering an injury that is expected to keep him out of action for 10 weeks. 

Borthwick admitted the British and Irish Lion will be sorely missed, despite England's depth at the position. 

"Mako's play has been exceptional. He's grown and grown over the years," Borthwick said. 

"He has a presence. 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 while Genge left training today he's also an excellent player."