England second row forward Courtney Lawes and mercurial Welsh centre Gavin Henson hope to seal their World Cup places when the two nations clash at the Millennium Stadium on Saturday.
Lawes was named in a much-changed England starting line-up for their second warm-up game against the Welsh.
After missing the Six Nations with a knee injury he was taken to hospital on a stretcher after a clash at an England trial match at the Twickenham Stoop two weeks ago.
He was on the ground for 10 minutes at the behind-closed-doors fixture and taken away in ambulance.
However the 22-year-old will not be holding back against the Welsh in the last England fixture before Martin Johnson has to name his 30-man World Cup squad.
"I am still going out there and if I see a tackle or a big hit I'll still go for it," said Lawes.
"I am going to concentrate on getting my hands on the ball and making my tackles. I was playing pretty well at the end of last season and hopefully I can take that into the World Cup.
"I thought it [the neck injury] was a fuss over nothing but the physios have to be careful when it is your neck."
England manager Martin Johnson rates Lawes highly and is excited about the youngster's impact on training recently.
"He is probably the most athletic second row I have seen in terms of pace around the field. He gives you line speed defensively and hits hard," said Johnson.
"He is developing into an all-round second row for a young man. He has got a good level of aggression about him and intensity. As someone said the other day - when he hits, you can hear him. It is a destructive noise."
England missed Lawes' athleticism in the Six Nations which ended with defeat in Dublin in March by which time the second row was fit.
But Johnson stuck with his side that had won four out of four for the Grand Slam match and Lawes finished the season frustrated.
Lawes is one of 13 changes made to England's starting line-up from the side that beat Wales 23-19 at Twickenham last Saturday.
Only wing Mark Cueto and prop Alex Corbisiero will have started both games while Johnson has released props Paul Doran-Jones and Tim Payne plus winger Ugo Monye back to their clubs to get some match practice in pre-season games after missing out on both recent Tests but insists they are still part of the squad.
Wales have given Henson a chance to make their World Cup squad after missing out in 2003 and 2007 by pairing him with Jamie Roberts in midfield for Saturday's match.
The 29-year-old centre, who has been struggling to rebuild his career, is still without a club side after his brief stay at Toulon ended in May.
And he admitted that Jamie Roberts, Jonathan Davies and Scott Williams are all ahead of him in the pecking order for the World Cup.
"Jamie, Jonathan and Scott are ahead of me," said Henson. "But once I get my chance it's up to me to try and turn the tables on that and that's what I'm hoping to do."
Wales coach Warren Gatland insisted a win is crucial on Saturday.
"We've told the players that for us to be regarded as contenders at the Rugby World Cup we need to beat England at home this weekend, to send out that message to everyone that we are contenders," he said.
"We have the toughest pool at the tournament and in less than a month's time we will be facing South Africa in our opening match."
Meanwhile, James Hook replaces fullback Morgan Stoddart, who broke his leg at Twickenham.
In the pack, Newport hooker Lloyd Burns gains a first start while Luke Charteris replaces Bradley Davies in the second row.
Players to watch:
For Wales: Injuries mean a reshuffled backline - with James Hook at fullback and Rhys Priestland at flyhalf. However, the player most people will watch is poster boy Gavin Henson at inside centre. Is he just a show pony or a real rugby player. He has talent, there is no doubt, but does he have the right mindset?
For England: Big and strong in the backs. That is how England like it. However, it is the halfback pairing of Toby Flood and Richard Wigglesworth that can spark these monsters. Hendre Fourie, like other fringe players, gets another chance to book a World Cup spot.
Head to head: This will be a classic - the quick-stepping little Welsh wizard Shane Williams against the tough-talking and swan-diving former Rugby League player from England Chris Ashton. The scrums could be interesting also - the wobbly Welsh trio of Craig Mitchell, Lloyd Burns and Paul James in the front row against England's Dan Cole, Steve Thompson and Alex Corbisiero.
2011: England won 23-19, London
2011: England won 26-19, Cardiff
2010: England won 30-17, London
2009: Wales won 23-15, Cardiff
2008: Wales won 26-19, London
2007: England won 62-5, London
2007: Wales won 27-18, Cardiff
2006: England won 47-13, London
2005: Wales won 11-9, Cardiff
2004: England won 31-21, London
Prediction: There i no doubt Wales can win - they have done it often enough in the past. However, England just seems so much more likely to win, especially after last week's effort at Twickenham - when they were well off the pace and still had enough in the tank. Wales seems to lack real depth in strength and they have a few key injuries. England to win by a more comfortable margin than last week - more than 10 points.
Wales: 15 James Hook, 14 George North, 13 Jamie Roberts, 12 Gavin Henson, 11 Shane Williams, 10 Rhys Priestland, 9 Mike Phillips, 8 Toby Faletau, 7 Sam Warburton (captain), 6 Dan Lydiate, 5 Alun Wyn Jones, 4 Luke Charteris, 3 Craig Mitchell, 2 Lloyd Burns, 1 Paul James.
Replacements: 16 Huw Bennett, 17 Ryan Bevington, 18 Josh Turnbull, 19 Justin Tipuric, 20 Tavis Knoyle, 21 Scott Williams, 22 Aled Brew.
England: 15 Ben Foden, 14 Chris Ashton, 13 Mike Tindall (captain), 12 Shontayne Hape, 11 Mark Cueto, 10 Toby Flood, 9 Richard Wigglesworth, 8 Nick Easter, 7 Hendre Fourie, 6 Tom Wood, 5 Courtney Lawes, 4 Louis Deacon, 3 Dan Cole, 2 Steve Thompson, 1 Alex Corbisiero.
Replacements: 16 Lee Mears, 17 Matt Stevens, 18 Tom Palmer, 19 James Haskell, 20 Danny Care, 21 Charlie Hodgson, 22 Matt Banahan.
Date: Saturday, August 13
Venue: Millennium Stadium, Cardiff
Kick-off: 14.30 (13.30 GMT )
Expected weather: Largely cloudy and staying mostly dry, but light drizzle still possible from thicker cloud. High 18°C, low 13°C
Referee: Alain Rolland (Ireland)
Assistant referees: Mathieu Raynal (France), Simon McDowell (Ireland)
TMO: Jim Yuille (Scotland)
AFP & rugby365.com
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