Daniel Riordan, Conor Muldoon, David Gannon and Mel Deane have all been called up since Connacht beat Dax last time out in January but head coach Michael Bradley is still wary of the threat posed by the Welsh side.
"They've a lot of strength in depth and despite missing some players with the Six Nations underway they'll still be able to field a very strong side," he said.
"We've two matches during the Six Nations against the Ospreys and Cardiff and know that we'll be facing some depleted sides and with that it mind it's an opportunity for us to get some championship points.
"The Ospreys are currently lying second in the table and they've shown some fine form in the Heineken Cup too, which has got them to the quarter-finals, so we know we'll have a very tough game come Sunday."
Connacht's extended squad includes four players who lined out for Ireland 'A' in their win over Scotland 'A' last week - Gavin Duffy, Keith Matthews, Sean Cronin and John Muldoon.
CONNACHT Squad (v Ospreys): Backs (12) - Liam Bibo, Kieran Campbell, Fionn Carr, Mel Deane, Andy Dunne, Gavin Duffy, Ian Keatley, Keith Matthews, Frank Murphy, Troy Nathan, Daniel Riordan, Niva Ta'auso.
Forwards (13) - Andrew Browne, Sean Cronin, Andrew Farley, Adrian Flavin, David Gannon, Ronan Loughney, Robbie Morris, Conor Muldoon, John Muldoon (capt), Ray Ofisa, Colm Rigney, Michael Swift, Brett Wilkinson.