The team and replacements will be announced on Thursday morning.
Speaking ahead of the game, Connacht captain John Muldoon said: "We've had three pre-season games and I think we used 30 or so players in total in those games, which is what pre-season is all about - getting guys on the pitch and getting the new guys bedded in.
"At this stage we can't wait to get out on the pitch and get a crack at them."
CONNACHT Squad (v Ospreys): Backs (10) - Fionn Carr, Gavin Duffy, Ian Keatley, Keith Matthews, Frank Murphy, Troy Nathan, Miah Nikora, Conor O'Loughlin, Niva Ta'auso, Brian Tuohy.
Forwards (12) - Andrew Browne, Sean Cronin, Adrian Flavin, Jamie Hagan, Mike McComish, Robbie Morris, John Muldoon (capt), Johnny O'Connor, Ray Ofisa, Michael Swift, Bernie Upton, Brett Wilkinson.