Paul James will captain the Ospreys when they play against Leinster in a critical PRO12 fixture at the Liberty Stadium on Friday.
James, who replaces Nicky Smith in the front-row this week, takes over the reins from Alun-Wyn Jones, who has been relegated to the Ospreys bench for this match. Rory Thornton, who was on the bench against the Dragons, will start in the second-row.
Ospreys head coach Steve Tandy has also introduced a completely new midfield this week, which features Jonathan Spratt and Owen Watkin. Making way for them are Ben John and Josh Matavesi.
Tandy has also made a pivotal change, with Dan Biggar assuming control at flyhalf, while Sam Davies will slot in on the bench. Brendon Leonard will start in the number nine jersey.
Both sides of the scrum will see new faces on Friday, as Sam Underhill and James King come in for Justin Tipuric and Dan Lydiate. Despite the plethora of changes, Tandy still thinks his team has the capacity to build on the momentum that was gathered during the Christmas period.
"We can look back at the Christmas period and be relatively pleased with the outcome from two difficult matches, even if we feel that we still have some way to go in terms of performance if we are going to achieve what we want to this season," he said.
The Ospreys coach is, however, under no illusions about the enormity of the task that lies ahead for his team this week, against a Leinster team which has a considerable amount to play for.
"It doesn't get any easier as we're up against the form team in the PRO12 on Friday night. Leinster had to deal with similar issues to ourselves at the start of the season due to their over contribution to the Rugby World Cup but have more than made up for that as they've played their way towards the top of the table. We know that we have to continue striving for excellence as a team, working hard as a collective, if we're going to keep heading in the right direction ourselves, starting on Friday," he added.
Opponents Leinster have not been shy with the changes either. Coach Leo Cullen has made six alterations to be precise and chief among them is the inclusion of Isa Nacewa on the right wing, where he will also operate as the captain. He replaces Fergus McFadden.
In addition Ben Te'o moves to outside centre this week, while Luke Fitzgerald slots in at 12. Garry Ringrose misses out completely.
Jamie Heaslip will start at the back of the scrum, at the expense of Jordi Murphy. Sean O'Brien slots in flank, where he will replace Josh van der Flier. Finally Marty Moore will get relegated to the bench, after being replaced by Tadhg Furlong in the front -row.
Form: Ospreys achieved a fifth successive Guinness PRO12 victory at home to Newport Gwent Dragons on New Year's Day. The Welshmen have not been beaten at Liberty Stadium since Connacht were the visitors in October. Leinster have won their last six Guinness PRO12 encounters since their 14-25 defeat to Scarlets in Llanelli in round 4. The Leinstermen are winless on their last four visits to Wales since beating Blues at BT Sport Cardiff Arms Park on 10 January 2015. Ospreys have won just one of their last seven fixtures against Leinster in all tournaments: 25-19 at Liberty Stadium in the PRO12 in April 2014, however Leinster have not been triumphant at the venue in the Guinness PRO12 since September 2009.
Ospreys: 15 Dan Evans, 14 Jeff Hassler, 13 Jonathan Spratt, 12 Owen Watkin, 11 Hanno Dirksen, 10 Dan Biggar, 9 Brendon Leonard, 8 Dan Baker, 7 Sam Underhill 6 James King, 5 Rory Thornton, 4 Lloyd Ashley, 3 Aaron Jarvis, 2 Scott Baldwin, 1 Paul James.
Replacements: 16 Scott Otten, 17 Nicky Smith, 18 Ma'afu Fia, 19 Alun Wyn Jones, 20 Justin Tipuric, 21 Tom Habberfield, 22 Sam Davies, 23 Eli Walker.
Leinster: 15 Rob Kearney, 14 Isa Nacewa (c), 13 Ben Te'o, 12 Luke Fitzgerald, 11 Dave Kearney, 10 Johnny Sexton, 9 Luke McGrath, 8 Jamie Heaslip, 7 Sean O'Brien, 6 Rhys Ruddock, 5 Mike McCarthy, 4 Devin Toner, 3 Tadhg Furlong, 2 Richardt Strauss, 1 Jack McGrath.
Replacements: 16 Sean Cronin, 17 Peter Dooley, 18 Marty Moore, 19 Tom Denton, 20 Dominic Ryan, 21 Eoin Reddan, 22 Ian Madigan, 23 Noel Reid.
Date: Friday, January 8
Venue: Liberty Stadium
Kick-off: 19:45 GMT
Referee: David Wilkinson (Ireland)
Assistant Referees: Ben Whitehouse (Wales), Simon Rees (Wales)
TMO: Jonathan Mason (Wales)