England hope to have Chris Ashton available for the final two rounds of their Guinness Six Nations title quest as the Sale wing battles a calf strain.

Ashton suffered the injury in training during the squad's three-day camp in London and will receive treatment at his club Sale this week, ruling him out of Saturday's showdown with Wales in Cardiff.

It is hoped the Sharks wing will return in time to face Italy and Scotland, however.

Jack Nowell was among the heroes in the 32-20 victory over Ireland but was demoted to the bench against France, enabling Ashton to make his first Six Nations start for six years.

Nowell is firm favourite to reclaim the number 14 jersey against Warren Gatland's title challengers, but another option is Joe Cokanasiga.

Cokanasiga played his first game for over two months in Bath's victory against Newcastle on Saturday having recovered from a knee injury and is in strong contention for a bench role at the Principality Stadium.

"Jack was very impressive against Ireland and brings a slightly different skill set to Chris. He's very capable in the air as well," Mitchell said.

"It was really important for Joe to get some rugby for Bath. It's always good to cross the line as a winger so that was probably very good for him mentally.

"Another week this week will prepare him even better. He's a big strong lad and is also good in the air as well."

England and Wales are the only teams with 100 per cent records in the Six Nations after two rounds, setting up a mouthwatering collision.

"Wales are pretty good and have been improving progressively over a long period of time under Warren," Mitchell said.

"They have a style of rugby that suits them and they're very comfortable with that.

"They're a very passionate rugby country.

"They enjoy moving the ball and have a lot of variety in their game as well, so that makes them a different threat."