The British Lions and Wales star produced a 20-minute cameo appearance against Ulster last weekend following ankle surgery and has been passed fit to start.
Coach Sean Holley said: "We need to see Gavin start a game and how he contributes to a match. He's been excellent in training and looks superbly big, strong, fast and powerful.
"But it's a lot to ask for him to play a couple of games and then be thrown into a major European competition. We will see how he responds.
"I'm excited to have him back on the field and we all know what Gavin can do. It could be a big season for him."
Henson is joined in the centre by fit-again Sonny Parker in a strong line-up containing 13 internationals but Wales forwards Ian Evans and Jonathan Thomas are rested.
Ospreys: L Byrne; J Vaughton, S Parker, G Henson, S Williams, J Hook, R Webb; D Jones, H Bennett, A Jones, I Gough, AW Jones, F Tiatia, R Jones (capt), M Holah
Replacements: R Hibbard, A Millward, L Bateman, S Tandy, T Smith, D Biggar, T Bowe
