It will be third against second at Sardis Road, with the home side also looking to make up ground on league leaders and reigning champions Merthyr, who are involved in the WRU National Cup Final at the Principality Stadium.
The Quins are currently two points behind the Ironmen, but have already played one more game than them.
They are also six points clear of Pontypridd, who also have a game in hand.
Pontypridd will be without scrum-half Jamie Hill and prop Will Davies-King, both called up to a Wales Under-20 training camp, but veteran outside-half Ceri Sweeney makes a return to the starting line-up.
He will have promising centre Alex Knott, from Nelson, outside him.
Llandovery host RGC 1404 at Church Bank in another vital game for both sides.
With at least one game in hand of the seven teams above them, the Drovers will jump three places with a win and could move to within one point of the Gogs in fourth if they pick up a winning bonus point.
Earlier in the week Aberavon were made to sweat in the second half of their 30-26 win at Ebbw Vale as the home side scored three tries after the break to close a 20-point interval deficit.
There was also an impressive away win for Bridgend at Llanelli (25-22), while Bedwas beat Bargoed 34-19 at home.
Teams
Pontypridd v Carmarthen Quins
Pontypridd: Lloyd Rowlands; Alex Webber, Alex Knott, Gary Williams, Dale Stuckey; Ceri Sweeney, Joel Raikes; Ian George, Huw Dowden, Kieran Assiratti, Sean Moore, Chris Dicomidis, Morgan Sieniawski, Rhys Shellard (captain), Hemi Barnes
Reps: Harry Rumens, Jordan Rees, Geraint Walsh, Joe Page, Sion Edwards, Shay Smallman, Huw Owen, Tom Mably
Carmarthen Quins: Aled Thomas; Dale Ford, Nic Reynolds, Josh Batcup, Morgan Griffiths; Jac Wilson, Aron Hemmings; Steff Thomas , Rhodri Clancy, Javan Sebastian, Josh Helps, Haydn Pugh (captain), Shaun Jones, Elis Lloyd, Shaun Evans
Reps: Steff Phillips, Tom Ball, Kemsley Mathias, Lee Taylor, Lawrence Reynolds, Lewys Millin, Jack Price, Dylan Morgans
Llandovery v RGC 1404
Llandovery: TBC
RGC 1404: Dion Jones; Afon Bagshaw, Tom Hughes. Tiann Loots. Rhys Williams; Jacob Botica, Alex Schwarz; Joe Simpson. Evan Yardley (captain), Sam Wainwright, Robin Williams, Andrew Williams, Will Bryan, Tim Grey
Reps: George Roberts, Jordan Scott, Charlie Connolly, Mei Parry, Dan Owen, Cameron Davies , Danny Cross, Ianto Pari
