CLYDESDALE BANK 40 GROUP A, The Oval:
Surrey v Worcestershire
Pietersen scored only 140 runs in England's four Tests against Pakistan
Kevin Pietersen will make his Surrey debut on Wednesday having signed a short-term deal following his omission from the England one-day team.
The England and Wales Cricket Board set up the deal so the 30-year-old gets match practice before the end of the season to get in shape for the Ashes.
Surrey manager Chris Adams said it was "exciting for everyone involved" and would "give a buzz around the team".
Pietersen is available for Surrey's last four games of the season.
His first appearance will be the floodlit
Clydesdale Bank 40 match against Worcestershire
at The Oval, starting at 1540 BST.
After making only 11 appearances for Hampshire in four years, he will officially leave the county at the end of the season and has said he would prefer to play for a team nearer his London home.
Following a disappointing display in England's summer Test series against Pakistan, he was axed from the side for the one-day and Twenty20 internationals.
Controversially, he leaked news of having been dropped and also his move to Surrey on his Twitter feed before either had been formally announced.
Pietersen will play for Surrey to improve his form ahead of the winter's Ashes series in Australia, starting in Brisbane on 25 November. As he is contracted to England, the arrangement is at no cost to Surrey.
He will arrive as Surrey's Steven Davies goes off to join the England limited-overs squad, and Adams said he was looking forward to having him on board, for however short a time it may be.
"From my perspective as team manager I'm losing Steve Davies but gaining Kevin Pietersen, so it's good player out, good player in," he said.
"It'll be exciting for everyone involved to have player of Kevin's quality around. The information and knowledge that will exist within him, we have to get out in the time that he spends here."
Surrey chief executive Paul Sheldon said: "We are very pleased to be in a position to have agreed to the ECB's request to assist Kevin's return to form."
England selector Geoff Miller said he stood by the decision to drop Pietersen for the limited overs games against Pakistan, despite him being named Man of the Series when England won the ICC World Twenty20 earlier this year.
"We know KP is a high-quality international player but his form has not been where he would have wanted it to be, so we've given him the opportunity to get some middle practice - with the Ashes in mind," he said.
When he leaked the news, Pietersen made his dissatisfaction clear in graphic language, and Miller said at least it showed his passion for playing.
"I'd expect Kevin to be disappointed," he said.
"We have to thank Surrey for accepting the request and we think that will benefit him more than some one-dayers - and I know he will fight his way back to be an integral part of the England side.
"I fully anticipate seeing Kevin Pietersen back to the way he was when he dominated opposition attacks.
"There are a few players who will be fighting to get into that side, and Kevin will be one of those."
As for the embarrassment of the twitter leak, Miller said he would be having words about it.
"I'll talk to KP. Whether there is an apology or not, I'm sure (England coach) Andy Flower will have a word with him," said Miller.
"If he wants to apologise or thinks there is a need to apologise then so be it. I will certainly explain to him what my feelings are."