Kevin Pietersen has said that Surrey's four-day clash with Yorkshire is an opportunity for him to gauge his return to full fitness ahead of the Ashes.

The 32-year-old has been sidelined with a knee problem since March, which has threatened his participation against Australia this summer.

However, the South African-born batsman will return to action for his country side at Headingley later today as he looks to prove his fitness.

"I'm just going up to Yorkshire to get through these four days," Pietersen told talkSPORT.

"The professional in me will want to score as many runs as possible, but the most important thing is to wake up each morning and know there is no issue with my knee and to know I've turned a big corner and can handle a day in the field.

"That's the only thing that's not been tested. I can bat in the nets and I've done all the fielding drills you can do, but it's not the same as being in the field for 90 overs."

The first Test takes place at Trent Bridge on July 10.