Rugby World Cup 2015: Warren Gatland expects 'physical' England

Warren Gatland took over as coach of Wales in 2007

Wales must not get drawn into a physical showdown with England at Twickenham on Saturday, according to head coach Warren Gatland.

England opened their World Cup with a 35-11 win over Fiji, while Wales were 54-9 winners over Uruguay.

Gatland says his team have to keep their tactics flexible while meeting England's fire up front.

"We've got to make sure that we're not dragged in to playing a game we don't want to play," said the New Zealander.

"I don't think there's much improvement [needed] at all, really.

"Next week is all about getting yourself mentally right for that physical confrontation.

"We saw the way England played against us in the Six Nations, we saw what they did on Friday [against Fiji].

"In the second half they went back to their forwards, they drove every single lineout. It's going to be a contest up front.

"It's going to be a mental, physical battle and we've just got to prepare for that."

Liam Williams played his first match since undergoing foot surgery in June when Wales played Uruguay

More injury worries

Wales - already without injured backs Leigh Halfpenny, Rhys Webb and Jonathan Davies - have further concerns after another bruising encounter at the Millennium Stadium.

Cardiff Blues centre Cory Allen scored a hat-trick of tries but tore a hamstring and is set to miss the rest of the tournament.

And with props Samson Lee and Paul James struggling with calf injuries, Wales could have to call up another prop before the match with England at Twickenham.

Twickenham an 'exciting' prospect

England have won the last two meetings, but Gatland has guided Wales to wins in Twickenham in 2008 and 2012, and Wales have a 50% success rate against them in all matches since Gatland was appointed coach.

"It's going to be a physical game and really, really tough up front with the crowd and the atmosphere, but as a player you have to be excited about it," he added.

"It's one of the best stadiums in the world and England have had success there.

"As a coach I've had a huge amount of success there and I look forward to going there.

"It's a challenge - a real challenge for us as coaches and for the players, and you've got to be excited about that challenge.

"That's what you're in professional sport for - these are the games you get up for because of the challenge you face."