The 46-year-old Pietersen, England's third-highest run scorer across all formats, was this month appointed as a specialist mentor to the white-ball teams ahead of the 2027 World Cup.
"I've got a pretty mad schedule, (but) I wouldn't say no," Pietersen said on Friday when questioned about stepping up for the Ashes.
"I have had a conversation with Stephen but I don't think that necessarily means I need to be in a dressing room.
"There's a lot of time in the lead-up to an Ashes series ... and there are conversations that can be had there.
"I've certainly had conversations with Flem about language that he would like me to use with the Test batters, going into South Africa, and then certainly into the summer next year."
The first Test of the 2027 Ashes series is scheduled to begin on June 18 at Trent Bridge in Nottingham.
An explosive middle-order batter, Pietersen scored nearly 14,000 runs across all three formats for England, who last won the ODI World Cup in 2019 on home soil.
However, his England career ended controversially in 2014 in the aftermath of the 5-0 Ashes whitewash in Australia, amid reported tensions within the dressing room and between the batsman and team management.
Pietersen was the team's top scorer in that series and, despite remaining keen to play for England, was told he was no longer part of the plans, bringing an acrimonious end to his international career.
"I'm 46, man. That stuff's so long gone. I'm a completely different person too," he said.
"I've been lucky to have worn every T-shirt an England cricketer can wear; the good, the bad and the ugly.
"There are parts to all of their careers (where) I think I could potentially help them stay away from the ugly."
In Pietersen's first series after returning to the set-up, England completed a 3-0 whitewash of a spin-heavy Sri Lanka side to replace India at the top of the T20 world rankings.
