Nottingham - Kevin Pietersen's attitude towards county cricket is threatening his international place, according to the man who helped kickstart the batsman's career in England.
Former South Africa all-rounder Clive Rice was a key figure in persuading the now 30-year-old Pietersen to join Nottinghamshire in 2001.
South Africa-born Pietersen quit the Midlands county in 2004 for south coast side Hampshire.
But in June the England star announced his intention to leave Hampshire at the end of this season for a team based nearer his London home.
Pietersen has not appeared in a first-class match for Hampshire since 2008 and the club refused a request from the England hierarchy to play him in a one-day match last weekend because he planned to be elsewhere next season.
Since becoming an England regular, Pietersen's lack of county cricket has rarely been an issue.
But he has now gone 21 innings in a row without a Test century after his dismissal for 22 in the second innings of the ongoing series opener against Pakistan at Nottinghamshire's Trent Bridge headquarters here on Saturday.
"You cannot play on the basis that you think you can just turn up at international level," Rice told Britain's Sunday Express newspaper.
"You have to do the work at first-class level to set yourself up and know that you're in form and confident," added Rice.
"Nothing can replace time in the middle, there's no substitute for it," added Rice, one of the word's leading all-rounders in the 1980s who captained both Nottinghamshire and South Africa's Transvaal to domestic honours.
Hampshire's decision to do without Pietersen last weekend meant he came into the first Test against Pakistan not having played since suffering a thigh injury during a one-day international against Australia at Lord's on July 3.
"By the time a Test comes around it's too late to find your form if you haven't been playing," said Rice.
"Everyone else in that side is playing regularly and if you're a selector you're picking guys that are in form today for tomorrow's game -- it's that simple.
"He has had a number of injuries in the last 18 months, which makes it even more important for him to prove his fitness in the county game."
England begin the defence of the Ashes in November and would dearly love Pietersen to have made a big score in the three remaining Tests against Pakistan before they board the plane for Australia.
But Rice warned Pietersen's England career could be in jeopardy even before the Ashes get underway.
"If he's not going to play county cricket then as a selector I just can't see how they can pick him in the team...If he doesn't sort this out then he could easily end up out on a limb."