A single point separates the two sides in Conference A of the competition and the winners of this clash will put themselves in pole position to reach a Champions Cup play off.
Butler is joined in the back row by blindside Sean O’Brien and Eoin McKeon at number 8, with John Muldoon named among the replacements.
There are a number of changes in the Connacht pack with Conor Carey coming in at tighthead and Shane Delahunt set to start at hooker. In the second-row lock Ultan Dillane returns to the starting team alongside James Cannon.
In the midfield Peter Robb who has recently returned from injury forms a partnership with Eoin Griffin.
The back three remains unchanged with Niyi Adeolokun and Matt Healy on the wings and Tiernan O’Halloran at full back.
Commenting ahead of the game, Connacht Defence Coach Peter Wilkins spoke of the importance of this fixture in determining his teams season. “"Ospreys are in the driving seat in terms of that final Champions Cup qualification spot. We see the season as very much alive, but we need to make sure we perform and put Ospreys under pressure on Friday”, Wilkins said.
“Ospreys are a similar side to what we encountered last week against Gloucester so after the disappointment of that defeat we have a huge opportunity this weekend”, Wilkins added.
(15-9) Tiernan O’Halloran, Niyi Adeolokun, Eoin Griffin, Peter Robb, Matt Healy, Jack Carty, Kieran Marmion, (1-8) Denis Buckley, Shane Delahunt, Conor Carey, Ultan Dillane, James Cannon, Sean O’Brien, Jarrad Butler (Capt), Eoin McKeon.
Replacements (16-23): Dave Heffernan, Peter McCabe, Dominic Robertson-McCoy, Gavin Thornbury, John Muldoon, Caolin Blade, Craig Ronaldson, Darragh Leader.