Neath will be without their injured scrum half Patrick Horgan with his place going to Richard Morgan, while Bridgend scum half Brendan Roach s battling against injury to be fit to play.
Fly half Matthew Jones has scored 37 points for Neath in their four matches in this season's competition, including 12 in the quarter-final win over Pontypridd by 27-18 at the Gnoll.
Bridgend have already scored 170 points in their four matches and touched down 25 tries in the process with fly half Austen Howells leading the scorers on 27 points.
Aberavon and Caerphilly have met on ten previous occasions in all first-class rugby with Caerphilly winning nine times, of which eight were in league play and the other was the sole cup clash.
The Wizards have injury worries in skipper Chris Gittins and scrum half Danny Hawkins. Their fly half Jamie Davies has scored 56 of their 151 cup points, while No 8 Richard Morris has now scored 99 tries for the club and right wing Daran Griffiths is just one behind.
The Cheesemen had a splendid quarter-final win over Swansea and Stuart Thomas has scored 55 points in their four games. Both hooker Tim Carless and lock Neil Watkins are unavailable and a hooker crisis takes youngster Peter Harrison into the starting lineup.
Bridgend v Neath (kick-off 1pm):
Bridgend: A Carter; M Jeffrey, S James, R Dyke, A Havili; A Howell, B Roach (capt); G Thomas, A Phillips, G Alexander, H Alford, M Powell, M Thomas, D Fitzgerald, N Strong. Replacements: P Smithson, A Bishop, G Leonard, R James, R Long, P Morgan.
Neath: G Morris; K James, E Seveali'i, W Mitchell, R Johnston; M Jones, R Morgan; P Jones (capt), D Poland, A Howells, M Jones, L Bateman, B Sinkinson, J
McPhail, H Jenkins. Replacements: To be named.
Aberavon v Caerphilly (Kick-off 3.30pm)
Aberavon: R Lewis; D Griffiths, D Hawkins, G Jones, R Price; J Davies, D Hawkins; M Harris, J Jones, P Breeze, D Owen, C Gittins (capt), J Purnell, R Morris, C Thomas. Replacements: D Francis, G Dix, J Owen, S Edwards, M Davies, P Morgan, A James.
Caerphilly: J Thomas; G Holmes, R Howells, R Boobyer, P Phillips; S Thomas, A Peggington; L Manning, P Harrison, G Liddon, M Workman, P Jones, S Gardiner, A Williams (capt), J Polutele. Replacements: S Heddington, I Carter, B Edwards, D Sweet, G Fox, T Guy, L Howells.