Wales tighthead prop Ben Evans completed his move to Cardiff on Wednesday.
Principality Cup quarter-final
Cardiff v Pontypridd
Friday, 4 April at Cardiff Arms Park, kick-off 1905 BST
The 21-cap man, who was released by cash-strapped Swansea last Friday, has signed a contract with the Blue and Blacks until the end of the season.
He goes straight into the Cardiff team for the home Principality Cup quarter-final clash against Pontypridd on Friday night in something of a grudge match - Ponty were also in talks to sign Evans.
Evans played Wales' first three Six Nations games this season, but dropped out of the squad after the loss to Scotland.
Cardiff have struggled in the front row this season, following a crippling run of injuries.
Spencer John, Gary Powell and Andrew Lewis are long-term injury absentees, meaning that coach Dai Young has been forced out of playing retirement on a number of occasions.
With the proposed Swansea-Neath regional side particularly strong at prop, Evans' move could suggest a long-term future in the capital in Wales' revamped rugby structure.
Coach Dai Young said: "Ben is a great acquisition for us. He is a proven international and I am delighted to welcome him back to a club he played for as a youth.
"We've always regarded him as a Cardiff man and initially he's with us until the end of the season and hopefully beyond that."
Cardiff have included all six of their Wales squad members for the visit of Pontypridd.
Martyn Williams, who captained Wales in Paris last Saturday, plays despite a niggling knee injury.
The flanker will had a scan on the troublesome knee on Tuesday, and will decide next week whether surgery is required.
Pontypridd coach Lynn Howells is short of cover at scrum-half. Gareth Baber will start, but recent signings Kevin Ellis and Dale Burn are both cup-tied.
Fly-half Neil Jenkins has aggravated a calf muscle injury and his chances of starting are rated at 50-50.
After missing out on the signature of Ben Evans, Ponty received more bad front-row news when it was announced that tighthead Duncan Bell would leave the club for Bath at the end of the season.
Cardiff: Rhys Williams; Nick Walne, Jamie Robinson, Pieter Muller, Craig Morgan; Iestyn Harris, Ryan Powell; Kenneth Fourie, Peter Rogers, Ben Evans, Heino Senekal, John Tait, Robin Sowden-Taylor, Emyr Lewis, Martyn Williams (capt).
Reps: John Yapp, Greg Woods, Luke Tait, Jim Brownrigg, Richard Smith, Nick Robinson, Matt Allen.
Pontypridd: B Davey; G Wyatt, S Parker, J Bryant, E Lewis; C Sweeney / N Jenkins, G Baber; G Jenkins, M Davies (capt), D Bell, B Cockbain, R Sidoli, G Lewis, M Owen, R Parks.
Replacements: M Rees, S Cronk, N Kelly, D Povey, C Sweeney / N Jenkins, J Lewis, M Nutthall.
Referee: Hugh Watkins (Birchgrove)