Williams, a Llanelli dentist who lives in Penarth, returned to the Swansea-based club this season after playing for Llanelli and Neath - fracturing a kneecap against Caerphilly two years ago while with the Welsh All-Blacks.
Last season's home match against Newport was played at the Morfa Athletic Stadium two miles away, but the home camp believe that their elevated wind-swept Parc Mawr pitch will give them an advantage that the wider Morfa pitch did not.
Exciting young Pontarddulais-based centre James Davies, loose-head prop Andy May and former Neath under-21 flanker Andrew Llewellyn are all players with a big future in the Bonymaen lineup, while scrum half Andrew Jacobs, formerly of Aberavon, Neath and Caerphilly, has returned both to fitness and top form.
The last two away wins in the league have jumped Bonymaen four places and hopes are still high for a top six finish - something which other than last season they always seem to manage.
Hooker Darren Poland has recovered from having 18 stitches in his upper lip and his understudy will be Stefan James, formerly of Bath University and Vardre, who has just had eight stitches removed from a head wound. Centre Gareth Noble and wing Nicky Bonham have both suffered bad knee injuries which made them unavailable for selection.
Cardiff have opted to rest all their Wales squad members.
Bonymean: D Williams; R Jones, G Rowlands, James Davies, C Batsford; Stuart Davies, A Jacobs;A May, D Poland (capt), N Evans, M Glover, S Miller, A Llewellyn, L Griffiths, R Duilio.
Replacements: G W Thomas, C Jones, D Thomas, R Perrett, S James, A McPherson, D Hills.
Cardiff: Donavan van Vuuren; Anthony Sullivan, Matt Allen, Pieter Muller, Dean Dewdney; Nick Robinson, Richard Smith; Peter Rogers, Greg Woods, Tim Payne, Heino Senekal, John Tait, Dan McShane, Dan Baugh, Robin Sowden-Taylor
Replacements: Aled Jones, John Yapp, Luke Tait, Emyr Lewis, Nick Walne, Liam Robert