He will be joined by Kevin Maggs who will make his first Ulster appearance after moving from Bath.
Maggs replaces Paul Steinmetz at inside centre while Pady Wallace moves to the bench to accommodate Humphreys at out-half.
The only change among the forwards is Matt McCullough's return to the starting line-up ahead of Rowan Frost.
ULSTER team : 15 - Bryn Cunningham; 14 - Tommy Bowe; 13 - Jonny Bell; 12 - Kevin Maggs; 11 - Andrew Maxwell; 10 - David Humphreys (VC); 9 - Neil Doak; 1 - Simon Best; 2 - Paul Shields; 3 - Rod Moore; 4 - Matt Mustchin; 5 - Matt McCullough; 6 - Andy Ward (Captain); 7 - Neil Best; 8 - Roger Wilson.
Replacements: 16 - Nigel Brady; 17 - Ronan McCormack; 18 - Rowan Frost; 19 - Campbell Feather; 20 - Kieran Campbell; 21 - Paddy Wallace; 22 - Paul Steinmetz.