Pupil and teacher will go head-to-head tomorrow with Fratton Park as their playground – past loyalties counting for nothing.
The irony is not lost on Stoke boss Pulis, who regards his opposite number as the greatest influence on his career.
It was then Bournemouth boss Redknapp who recruited Pulis in 1987 to fire up his division three challenge – the tough-tackling midfielder responding by inspiring them to the title.
He was later made Redknapp's assistant. And when the Cherries boss departed for West Ham in 1992, he convinced the board to appoint Pulis as his successor. Today his protégé has carved out a reputation as a manager for working wonders on a shoestring during spells at Gillingham, Plymouth and – for 10 brief months – Pompey.
Now he's relishing returning to Fratton Park and reuniting with the man he credits with starting it all.
He said: 'You couldn't have a better education than just being close to H and watching how he works.
'He's taught me more than anyone. He's just a football nut. He loves his horses and loves a bet but he's absolutely crazy about football.
'I played under him and was coach alongside him and perhaps the biggest thing I have gleaned was when I was at Bournemouth.
'He was a great coach, not just a great manager. He knew every player at that club.
'We would go scouting practically every day of the week, spending hours driving up and down the country, and he would pull out his Rothmans Yearbook and just reel off player after player.
'He would certainly put the hours in. I actually think he's very, very underestimated.
'Just look at the fantastic jobs he has done.
'H is a strong character as well, he's not a weak manager.
'He even had the balls to go back to Portsmouth and take over again. Not many would.
'It's the overall package with H, though. He treats people very well. He's got a sma-shing demeanour about him.
'He sets high standards and if you drop he lets you know.
'This is a manager who came from a great, great gro-unding at West Ham. People like John Lyall and Ron Greenwood, what tremendous influences they have been.
'His enthusiasm and understanding of the game stands out above most.'
Redknapp may have achieved more success than Pulis during his Fratton days, but the club still holds fond memories for the 50-year-old.
After taking over in January 2000, with the Blues facing relegation, he recruited the likes of Shaun Derry and Kevin Harper to lead them to safety. But by mid-October, he was another Milan Mandaric casualty, despite winning more games than he lost in his 35-match reign.
But Pulis bears no malice.
He added: 'Portsmouth is a great club, a smashing place, I really enjoyed it there.
'It has got fantastic tradition and the supporters are very special, they love their football.
'You don't see too many people walking around the city wearing United shirts, they support their own club.
'I remember taking over on January 13 and we were second from bottom.
'We brought in five players and managed to change it round to stay up.
'Five months later I was sacked – and three of those were the close season. The problem was we weren't top of the league after 10 games.
'I've got no grudges towards Milan, though. He sent me a lovely letter when Stoke won promotion.
'I think he's a smashing fella, just as long as you do not have to work for him.'
Never miss a Portsmouth FC story... Get them sent straight to your e-mail inbox.... click here to subscribe.
The full article contains 650 words and appears in The News newspaper.