Pontypridd offer six members, and Swansea four to Steve Hansen's 32-man squad, but international relationships will be forgotten for 80 minutes as both sides seek to improve their positions in the table.
Both sides have recorded two wins; though Swansea have played six times compared to Pontypridd's four in this season's Welsh Premiership.
But the Valley Commandoes will head to St Helen's knowing it has been a huge bogey ground for them over the years - Pontypridd have won two and drawn one of their last four visits to St Helen's after having previously failed to win in almost 30 years. Swansea's last home win was against Neath on December 27, 2002.
Team manager Nigel Bezani could not recall ever being on the winning side there.
"It was the only major ground I ever failed to win on and Swansea always seemed to up their game against us. But, in the last few years, since I retired, we have had a bit of success there," he said.
Pontypridd coach Lynn Howells agreed with Bezani: "The press will have got Swansea's back up with recent comments and I expect a reaction from them. Their players will know that the one place they have to do their talking is out there on the pitch.
"It is worrying, in that I am sure they will be out to show that they are not that bad a side and I do expect a backlash from them."
Both men paid respect to their fly half Ceri Sweeney, who has received a call-up to the Wales squad, just two weeks after his 23rd birthday. "Great news," said Bezani.
"We have been thinking about this for some time. Ceri has worked well with Neil Jenkins in training and his play has been good for us this season."
Howells added: "Ceri's game has developed his whole game. He now is dictating and has a high profile. He and Neil are very close and very good friends. His inclusion is thoroughly deserved."
Both men also praised the club's scrum half Paul John for his part in bringing Sweeney on with Bezant saying: "Paul wants to play every match. He is the ultimate professional."
Howells would not name a team at this stage with forwards Brent Cocktail and Geraint Lewis still needing tests and Emir Lewis just recovering from a rib injury.
"I have assured Steve Hansen that I will not use my Wales squad players in the cup on Saturday, unless our injury list grows so bad that we just have to name one or two. Having been connected with the squad, I know how Steve feels and I respect that. We agreed that after Tuesday we would rest them".
There will be chances for young players such as Shaun James and Wayne O'Connor and Bezani commented: "There is good competition for places all round in our squad, despite the many injuries we have suffered."
Swansea will certainly be ready after losing all three matches this year, firstly against Llanelli, then Montferrand in the Heineken Cup and finally to Cardiff - the last two at St Helen's, where they also lost to Bridgend at the end of December.
It could well be a battle with Swansea just having to improve and Howells rightly knowing that a combination of pride by the All-White players and the bogey ground meaning that Pontypridd may have to be at their very best to get a result.
SWANSEA v PONTYPRIDD (at St Helen's, 7.00pm).
Pontypridd: Brett Davey; Gareth Wyatt, Shaun James, Jason Lewis, Richard Johnston; Ceri Sweeney, Paul John; Neil Hennessy, Mefin Davies (capt), Sven Cronk, Robert Sidoli, Michael Owen, Nick Kelly, Richard Parks, Geraint Lewis.
Reps: Geraint Morris, Matthew Rees, Dale McIntosh, Wayne O'Connor, Gareth Baber, Neil Boobyer, Matthew Nuthall.