Ospreys are without a win in their last three matches going into their Magners League clash with Munster.
After defeat against the Dragons last week the Welsh side have made a number of team changes.
"We wanted to freshen things up a little bit in terms of selection, there are some boys who have performed well who we felt deserve a chance in a game like this," said forwards coach Jonathan Humphreys.
The Ospreys are presently in fifth place and need a victory to keep them in the hunt for a semi-final place.
"It's the time of year when it's all or nothing," added Humphreys.
"We have to get two wins and hope that the Dragons can continue to perform like they did against us. If that happens, then we'll be in the play-offs, but it's going to be tough."
Meanwhile Munster's international contingent who sat out last week's game in Llanelli will be on board when the team travels to Wales to take on the Ospreys at the Liberty Stadium.
Captain Ronan O'Gara, Keith Earls, Donncha O'Callaghan and David Wallace all start this time around while Felix Jones, Doug Howlett and James Coughlan are also included in a starting XV that shows fourteen changes, three of those positional, from last time out.
In the backline the inclusion of Jones means a switch to centre for Paul Warwick with Lifeimi Mafi switching to thirteen in the absence through injury of Johne Murphy.
Up front only two of those who featured from the start against Scarlets, Marcus Horan and Donnacha Ryan, are retained with Ryan packing down this time in the back row.
Already qualified for a home semi final, the objective for Munster will be to maintain their good recent form.
"It's all about momentum and keeping that as we go into the final stages of the season," said Damien Varley.
"We have the semi-final of the Amlin the following weekend and this game couldn't come at a better time in that context. There is also huge competition for places in the squad so everyone's playing for their place and looking for a good performance to stake a claim for inclusion next time around."
Form:Ospreys are without a win in their last three matches, and have only once before gone four winless league games: in their debut season in 2003/04. Ospreys are unbeaten at Liberty Stadium since Dragons were the visitors and victors on 30 October 2010. Munster have already ensured that they will top the league after the regular season and thereby qualify for a home semi-final in the Magners League Play-Offs. The Munstermen have won their last four away games in all competitions. Munster won 22-10 when the two teams met in Limerick in round three, whilst each side won its respective home game when they clashed in this season's European Cup. No Irish team has won at Liberty Stadium since Leinster did so on 18 September 2009.
Ospreys: 15 Lee Byrne, 14 Nikki Walker, 13 Tommy Bowe, 12 James Hook, 11 Richard Fussell, 10 Dan Biggar, 9 Rhys Webb, 8 Jonathan Thomas, 7 Marty Holah, 6 Justin Tipuric, 5 Alun Wyn Jones (c), 4 Ian Gough, 3 Adam Jones, 2 Richard Hibbard, 1 Ryan Bevington.
Replacements: 16 Huw Bennett, 17 Paul James, 18 Duncan Jones, 19 Ryan Jones, 20 Jerry Collins, 21 Mike Phillips, 22 Andrew Bishop, 23 Sonny Parker.
Munster: 15 Felix Jones, 14 Doug Howlett, 13 Lifeimi Mafi, 12 Paul Warwick, 11 Keith Earls, 10 Ronan O'Gara, 9 Connor Murray, 8 James Coughlan, 7 David Wallace, 6 Donncha Ryan, 5 Donncha O'Callaghan, 4 Ian Nagle, 3 John Hayes, 2 Damien Varley, 1 Marcus Horan.
Replacements: 16 Mike Sherry, 17 Wian du Preez , 18 Tony Buckley, 19 Tommy O'Donnell, 20 Niall Ronan, 21 Peter Stringer, 22 Danny Barnes, 23 Simon Zebo.
Date: Saturday, April 23
Venue: Liberty Stadium
Referee: Jerome Garces