Former Australia spinner Warne will captain the Rest of the World against an MCC side led by Sachin Tendulkar, with a number of star names from the sport turning out for both teams.
Pietersen, a former Hampshire team-mate of Warne's, will be the main focus of England fans inside Lord's for the game, with his exile from the team continuing to divide opinion.
The 34-year-old was dropped from the England team ahead of a tour of the Caribbean in February, with captain Alastair Cook thought to be one of the main movers behind Pietersen's exclusion.
Since then the South Africa-born batsman has said he remains available for selection and Warne believes he will not lack for motivation.
"KP is an absolute match-winner," said Warne.
"He is a superstar and a wonderful player. He is fantastic to watch, I'm sure he will turn it on on Saturday and smash it all over the park. He has played well over the years at Lord's in his time with England and hopefully he can do that on Saturday.
"With the guys we have in the side they are pretty special and we all have egos but we will all be keen to impress and to show what they have got with the bat or the ball.
"I'm sure one or two players in the Rest of the World side will be keen to get out there and score a lot of runs. It will be pretty relaxed, everyone knows everyone. We want to win, Sachin's team wants to win so we will enjoy the game."
Warne and Pietersen will be joined by the likes of Adam Gilchrist, Muttiah Muralitharan, Yuvraj Singh and Paul Collingwood, whilst Tendulkar's MCC team includes names such as Rahul Dravid, Brian Lara and Brett Lee.