England must decide whether giant Fijian-born wing Joe Cokanasiga is ready to make his presence felt in Saturday's Guinness Six Nations title clash with Wales.
Cokanasiga is competing with Ben Te'o for a bench role at the Principality Stadium after completing a try-scoring comeback from a knee injury for Bath against Newcastle last weekend.
The 21-year-old made two Test starts last autumn and offers a powerful ball-carrying option off the bench, while Te'o covers both midfield positions and with 16 caps is more experienced.
Assistant coach Neal Hatley said: "Joe's hitting hard and carrying hard, so he brings good physicality on the wing.
"Joe's come in off the back of that game against Newcastle and physically looks very good. He's worked hard.
"As we saw over the autumn he brings physicality. For a big man he moves exceptionally well. Defensively he's getting better as well."
England must also decide between Ben Moon and Ellis Genge at loosehead prop after Mako Vunipola was ruled out of the Six Nations by an ankle injury.
Moon is a strong scrummager and can make a big impact in defence while Genge is a more aggressive carrier.
The last outstanding issue is who out of number eight Nathan Hughes and blindside flanker Brad Shields offers back row cover from the bench.
Cardiff will host the battle between the Six Nations' only unbeaten sides.
And hooker Jamie George is drawing strength from England's confrontational but measured approach.
"That's what we've done really well over the last few weeks – being on the edge of aggression constantly but having cool heads," George said.
"That's been a strength of ours, in the autumn and then coming into this. The Principality Stadium is going to be a cool place to play, a great atmosphere.
"We've got to be right on the edge again to make sure that we are nice and physical and do what we want to and put our stamp on the game in the way we want to.
"It's an amazing fixture, isn't it? When you look back at the history of the game, it's the game that most people get excited about, come Six Nations time, especially when it's in Cardiff.
"It's always a very competitive game and we know how good they are at the moment, so it's going to be a big one."
