NEW Wales coach Warren Gatland will send his troops into battle against England at Twickenham on Saturday with a few short, sharp words ringing in their ears - self-belief and confidence.

"That is the message I'm trying to get across. If one or two players don't have that it can spread through the team like a cancer," he warned.

"The boys need to have confidence collectively and individually so that they can deliver a performance, then it'll be a close game."

Eagle-eyed Gatland quickly spotted some potential weaknesses in the England line-up within minutes of it being announced.

"(Luke) Narraway is a bit of a surprise at number eight and (Andy) Gomarsall has not played a lot recently," he said.

"We have looked at their back three. Balshaw played on the wing last week, and I wasn't impressed with him at all.

"I have been impressed by David Strettle - but neither Lesley Vainikolo nor Paul Sackey has the greatest kicking game.

"That is one area we are going to see what they like, by putting the ball in beyond them to see how they respond. That's one area we'll have a look at, we'll put the ball in the air and behind them."

But Gatland will warn his team about the Jonny Wilkinson factor. "His kicking game out of hand or at goal is big, so we've got to be strong defensively and our discipline is hugely important. We've got to limit the number of penalties and Wilkinson's kicking opportunities," he said.

Earlier, Gatland explained to a shocked media why he had gone for as many as 13 players from the Ospreys, most expecting Tom Shanklin and Gethin Jenkins to be included, though Dwayne Peel was ruled out by a shoulder injury.

"I just picked a Welsh team not who they played for. The team was picked on form and I've taken into consideration combinations while others like Dwayne Peel were injured or had not played a lot," he said.

"But it is 22 players and the guys on the bench will get an opportunity. Also there has been little preparation time and there are other coaches like Robin McBryde, Shaun Edwards and Rob Howley, it's not just my team.

"It's not about where they come from but about picking players to do the best job. When I was with Ireland, Munster were playing particularly well, but we tried to balance the numbers and it wasn't the right thing to do.

"The Sonny Parker selection was on the toss of a coin. He has been a permanent fixture for the Ospreys while Tom (Shanklin) has been on the bench and on the wing."

Gatland said: "A lot has been based on the short preparation time and guys being comfortable with one another. It's been about prioritising and structures, about trying to cover as much as we can.

"But we've got to go out and have the confidence and self-belief we can deliver a performance because as soon as self-doubt creeps in, it can be a real negative and it could be a long afternoon for us."