Matt Prior is determined to prove he is England's best wicketkeeper-batsman during the NatWest Series against South Africa.

The 26-year-old Sussex player will train, weather permitting, with the rest of England's one-day squad at Headingley in preparation for Friday`s day-night opener to the five-match series.

It is an important match for England as they prepare for life under new captain Kevin Pietersen, but it is also a key opportunity for Prior as he attempts to re-establish himself at international level.

Dropped last year after a series of wicketkeeping blunders despite averaging more than 40 in Test cricket, Prior has watched former county team-mate Tim Ambrose also struggle to cope with the demands of playing for England.

But he is determined to prove his time in county cricket, where he averages 58 in the top division of the championship for Sussex this season, has not been wasted and he will return a better player.

"The way I viewed it (bring dropped) was that it's reality," he said. "You can either sulk and blame everyone else or say what do I want to change and how do I go forward?

"I don't want to go back there, so I answered those questions.

"I think it makes you stronger. I think an experience like that does change the way you think and your attitude towards a few things and you grow up a bit.

"My family stuck by me throughout and you learn who your friends are in that situation. I'm lucky a few people stuck by me, but I don't think I changed that much."

His immediate objectives are to score consistently in the coming series to boost his claims for a place in the squad to tour India before Christmas.

Prior also remains in contention for a place in the Champions Trophy squad should safety concerns about the tournament in Pakistan be resolved between the various national boards and the International Cricket Council.

So far Prior has under-performed in one-day international cricket and in 23 appearances - all but two of which have been as opener - has reached 20, normally a score that suggests a batsman is now comfortable at the crease, 11 times but has only scored one half-century.

It is a record Prior is keen to improve upon in the five matches ahead, saying: "The frustrating thing for me looking back is that I always got starts.

"I managed all the hard work - I saw off the new ball, got 30s or 40s but didn't kick on.

"I think the important thing for me as an individual and for the team is to keep on batting and get the hundreds that put you in a good position to win games."

He added: "When I was left out my goal was to get on a winter tour and that hasn't changed.

"I said to myself 'if anything happens before then, fantastic, but my goal is still to get on a winter tour'."