The Quins top the table with a tally of 55points, three more than Pontypridd but having played two more games.
The hosts know that games in hand are worth little if not won and that a tough challenge awaits as the 'best of the west' come visiting the House of Pain. Pontypridd secured a valuable away win by 8-25 at Carmarthen back in late November.
The latest injury victim for Pontypridd is prop Pat Palmer with neck disc problems, whilst a number of players are away on international duty - hooker Liam Belcher with Wales under 18s, scrum half Tom Williams with the under 20s and flanker Rhys Shellard and winger Owen Jenkins with Wales Sevens.
Club captain Dafydd Lockyer, recovered from a recent shoulder injury, resumes at centre, with outside half Simon Humberstone drafted in from the Blues squad and prop Lewis Jones from Abercwmboi, both on the bench.
Second row stalwart Craig Locke will make a landmark 100th appearance for his club.
Pontypridd 15.Aled Summerhill. 14.Owen Williams. 13.Geraint Walsh. 12.Dafydd Lockyer - cpt. 11.Matthew Nuthall. 10.Dai Flanagan. 9.Lloyd Williams.
1.Chris Phillips. 2.Aled Morris. 3.Keiron Jenkins. 4.Craig Locke. 5.Jordan Sieniawski. 6.Owen Sheppeard. 7.Wayne O'Connor. 8.Dan Godfrey.
Subs: 16.Gareth James. 17.Simon Humberstone. 18.Garyn Smith. 19.Tom Hetherington. 20.James Cashin. 21.Luke Crocker. 22.Lewis Jones. 23.Bradley Thyer