Dylan Hartley and Brian Mujati were once part of one of the most fearsome front rows in European rugby history.
But this weekend, when Saints face Racing Metro in Paris, the duo are set to go head to head as they bid to shove each other out of the game.
Back in the 2010/11 season, Hartley and Mujati, along with Soane Tonga’uiha, made a habit of making mincemeat of opposition packs.
Their power propelled Saints to the Heineken Cup final, where, had it not been for a seemingly immortal Leinster side, European glory would have been claimed.
Jim Mallinder’s men had taken on - and pummelled - all-comers during that campaign, winning all of their games on the road to Cardiff.
And the bedrock of their success was a pack that left opposition eights stuck in reverse.
“For me, that Heineken Cup run was one my most enjoyable seasons,” said Hartley in the build-up to Saturday’s Rugby Champions Cup opener at Racing.
“We really felt the force of the town. We played in Milton Keynes (in the quarter-final and semi-final) but the big games we played there were brilliant.
“The momentum was all our way and it was unbelievable but then, one man, Jonny Sexton, and his Leinster mates turned it around in that half of rugby and it’s one I’d like to forget. But that season was really enjoyable.”
Saints will get a sharp reminder of some of the Heineken Cup memories they had tried to banish when they face Racing this weekend.
Sexton is in the home ranks and Ronan O’Gara, whose drop goal long after the clock had gone dead earned Munster a memorable win against Saints in 2011, is on the coaching staff.
But it is Mujati and Juandre Kruger, another popular ex-Saint, who will command the attention of the travelling support this weekend.
And Hartley has fond memories of both.
“They’re both good blokes,” he said. “I’m looking forward to having a catch-up with Brian afterwards, hopefully share a home brew if he’s got some spare.
“He came back from injury last week and played so hopefully he’ll be in their team.”
Mujati became a cult figure during his four-year stay at Franklin’s Gardens, with cries of ‘Mooj’ often ringing around the ground on matchdays.
And Hartley said: “Your tighthead in a team is your lynchpin. He’s your barometer of how a game’s going to go. When our scrum is going well, the rest of it is going well.
“Mooj and Soane were very physical up front. We played some big games and we got some big scrums out of them.
“It’s quite nice to see people recognise a tighthead. He was a firm favourite here and I’m sure he still is.”
And Hartley still keeps up to date with Mujati’s antics via YouTube, on which the Bulawayo-born prop has a video diary called The Life of Brian.
“I’ve learned a lot about bodybuilding and a lot about brewing beer,” said the Saints skipper, smiling.
“I don’t really have a massive interest in either, but I’ve got an interest in Brian. He’s an interesting character and I do follow him.”
This weekend, Hartley will hope to do more than that.