Jos Buttler has admitted that he must improve to play Test cricket for England after he was left out of the squad to face Sri Lanka.

There were calls for the Lancashire wicketkeeper to be selected ahead of Matt Prior for the two-match series due to his impressive displays in limited-overs games, but he concedes there are areas he needs to work on if he is to make the step up to the longest format.

"I've got some improvements to make in both sides of my game," Buttler told BBC Radio 5 live. "With the batting it's working out the best method to score big runs against the red ball.

"I don't want to lose that attacking side of my game but I may have to be a bit more selective.

"And wicketkeeping, I've got lots of areas to improve on that as well - becoming a bit more consistent."

Buttler has scored just three centuries in 51 first-class matches.