Alastair Cook: 'Jos Buttler not ready for Test cricket'

England captain Alastair Cook has played down speculation surrounding Jos Buttler and the Test team.

In recent months, reports had claimed that the wicket-keeper would feature in the upcoming five-day series with Sri Lanka, and the clamour grew yesterday with his knock of 121 in a one-day international against the same opposition.

However, Cook believes that the 23-year-old still has improvements to make before he can be considered for the longer format of the game.

"He's certainly found his method in one-day cricket. He knows what he's doing. I think he's yet to find that in four-day cricket," said Cook. "I think he'll be honest with himself, he needs more time to do that. But a guy who is as talented as that, there's no reason why he can't.

"I think he will become a very good Test player at some stage for England. Talented people find ways to do that, but I don't think he's quite ready yet for that role."

Providing that he can prove his fitness, it's expected that Matt Prior will take the gloves for the Sri Lanka encounters.