Gatland has picked 13 Ospreys players in his squad

Full-back Balshaw was the surprise pick ahead of Mathew Tait, who played centre in the World Cup final but was expected to replace Jason Robinson at 15.

"We have looked at their back three," said Gatland.

"Balshaw played on the wing for Gloucester last week, and I wasn't impressed with him at all."

Gatland also believes new England recruit Lesley Vainikolo and winger Paul Sackey are a vulnerable part of the England team and can be targeted by his side.

Andrew Sheridan is one we're going to really have to watch Warren Gatland

"I have been impressed by David Strettle - but neither Lesley Vainikolo nor Paul Sackey, who will start on the wing, has the greatest kicking game," said Gatland.

"That is one area we are going to see what they like, by putting the ball in beyond them to see how they respond."

Gatland is wary about the impact of prop Andrew Sheridan but will be making the referee aware of the fouls he believes Lewis Moody concedes.

"Up front, England are going to be a tough unit," he said. "Sheridan is one we're going to really have to watch, his ball carrying and scrummaging is some of the best in the world.

"As a unit there's not too many weaknesses, they've got so much strength in depth and self belief but we've got to go there and match that."

He added: "One of the things about Moody is that you can guarantee two or three penalties against someone like him because traditionally he's that sort of player that you question his discipline and the number of penalties he gives away in matches.

"I'd like to highlight that with the referee, it's important at the tackle area that you can recycle and keep it legal."