Henderson returns in place of Mike Mullins and partners Shaun Payne in the centre while John Kelly remains on the wing.
In the pack O'Connell replaces Tom Bowman in the Engine room while Williams slots into the back row.
Speaking on Munster's website Gaffney said; 'Denis and Jim have been outstanding in their appearances to date. Last week we felt Denis needed a rest and Jim wasn't available but now he is. There is also the question of giving players the opportunity to stake a claim and to that end we are trying to give squad members as much game time as possible.'
Munster: Cullen, Kelly, Payne, Henderson, Horgan, O'Gara, Stringer, M. Horan, F. Sheahan, J. Hayes, O'Connell, Hogan, Williams, Leamy, Foley