Jos Buttler admits he is not ready for Test cricket with England

The wicketkeeper-batsman smashed an incredible 121 off 74 balls to bring England within a whisker of winning Saturday's fourth one-day international against Sri Lanka at Lord's - which would have rounded off a series triumph.

He fell just short in his quest though, being run out in the game's final over, having required 10 runs against Lasith Malinga's expert death bowling.

England return to Lord's on June 12 for the first of two Tests against Sri Lanka with doubts over the fitness of regular keeper Matt Prior, who is suffering with an Achilles injury.

Despite that, captain Alastair Cook was quick to cool talk that Buttler could make the step-up immediately, something the Lancashire man agrees with.

"I haven't discussed it with the management or Alastair," he said. "(But) I am not ready for Test match cricket.

"It is a pretty easy assumption to make, looking at my game and where I am as a player.

"That is my honest opinion, and that is the opinion of others."

Though Buttler is not expecting a Test call-up any time soon, the 23-year-old is determined to make an impression on the longest format of the game eventually.

"It is my hope and ambition to turn into someone who is talked about as a Test cricketer as quickly as I can," he added.

"I average 32 in first-class cricket and, if I wasn't playing one-day cricket, I would not be at the forefront of anyone's mind with an average like that.

"My glovework needs to improve too, to be a Test match cricketer.

"You have to remember it takes time. You can't be a finished article at 23. You want to accelerate your development, but you want to be realistic as well."