Wales assistant coach Rob Howley has admitted that Warren Gatland has a "selection issue" to deal with following Rhys Webb's return.
However, Gareth Davies has shone in his absence, including scoring five tries in the World Cup, and Howley was keen to talk up the importance of Wales's strength in depth at scrum-half.
"We have called Rhys into the squad, and it's nice to have someone of his quality. He brings experience, patience and composure. We watched him against Leinster [for the Ospreys], and he probably needs a little bit more time under his belt, and we will gauge that over the next 24 hours to decide whether we use him or not next weekend," Howley is quoted as saying by PA.
"But let us not forget the impact Gareth has had. The experience that Rhys brings is something any side will want in selection, but Gareth has been going really well and played particularly well against France. He has been fantastic. There is no substitute for speed or the ability to create breaks, and that is what Gareth has done in abundance. He has been outstanding for us, and people forget he is still relatively inexperienced at international level.
"I said to Rhys that competition for places is to an extent where it's bringing out the best as players, and it makes people better players, including [Wales squad scrum-halves] Aled Davies and Lloyd Williams. It's a selection issue when you are a coach that is nice to have. It is not a headache, and it's important to have that quality in the team."
Wales would leapfrog England at the top of the Six Nations table with a victory at Twickenham.