Paul James will captain the Ospreys this weekend as Rhys Webb, Dan Lydiate and Scott Baldwin return to face the Scarlets.
Ospreys head coach Steve Tandy said: "The Scarlets game is always huge for us and our supporters and this weekend is no different. We know the Scarlets are coming here full of confidence so it's important that we rise to the challenge.
"It's been a difficult year, as we always knew it would be, but we've seen in adversity that we have a great spirit and some incredible young talent coming through, boys who are just 19, 20, 21, 22, who are getting some fantastic experience under their belt and showing that they can compete at the highest level. Yes, we've got some fresh injury concerns with 12 players unavailable, but are strengthened by some real quality coming back into the group from international duty. This is a chance, against a side who have been at the top all season, for these players to really say something about who we are and what we want to achieve, this year and in the future.
"We've got five games left and the target has to be to win all of them. With three at the Liberty, and the other two games being derby matches in Wales, you can't stress enough how important the supporters are going to be. We've been fortunate enough to enjoy some fantastic occasions and atmospheres at the Liberty, and on the road, already this season. This weekend we're going to have the biggest crowd of the season with an atmosphere to match. Our supporters, who are always fantastic, have a huge part to play, so it's important that they get right behind the team when they need them.
"We've got to enjoy this challenge, and really step up to the mark. If we are going to get what we want, starting with the Scarlets on Saturday, then our prep has to be spot on, we have to know our roles, do our homework, and be relentless in everything we do, during the week and in the game, and our attention to detail and accuracy has to be up several levels from where it was at times against Leinster, from the very first whistle.
"Get those things right, get the performance where it needs to be, that's our target, and the reward should come.”
Meanwhile, Scarlets captain Ken Owens returns to lead the side and he’s joined by internationals Gareth Davies, Rob Evans, Jake Ball and John Barclay in the starting XV with Samson Lee named on the replacements bench.
Liam Williams misses out on the clash with a hamstring strain whilst Morgan Allen returns to the number eight berth after recovering from a foot injury.
Speaking ahead of the derby earlier this week head coach Wayne Pivac said: “Our whole season has been built on improving on last year, we’ve made no secret about it – we want to improve. One of those improvements is our statue within Wales and we’d like to be King of the group if you like. Highest up in the points table and in doing so finishing in the top four.
“The self-belief is growing in the group, there’s a lot for us to play for selfishly, place in Europe like everybody and top four. We’re in there but it’s a case of improving week on week.
“Ospreys are a very proud team as we all know. They’re still within a very good chance of getting in to Europe and upsetting a few teams along the way. It’s a massive game for them as it is for us and we’re expecting a titanic struggle.
“It’s a derby against our close neighbours and there’s a lot riding on the game.”
Form: Ospreys have slipped to successive defeats in the PRO12, away at Connacht and Leinster, but at Liberty Stadium the Welshmen have suffered only one reversal in their last nine matches in all tournaments: 9-22 to Leinster in Round 12 of the PRO12. Scarlets have lost just one of their last four PRO12 fixtures: 23-24 to Edinburgh at Murrayfield in Round 16. Scarlets only victory in their last four away games in the tournament was by a single point at Ulster on February 21. Ospreys only defeat in their last seven encounters with Scarlets was 10-22 at Parc y Scarlets in January 2015. Scarlets only previous victory at Liberty Stadium was 14-9 in the PRO12 in September 2007.
Ospreys: 15 Dan Evans, 14 Jeff Hassler, 13 Ben John, 12 Josh Matavesi, 11 Eli Walker, 10 Sam Davies, 9 Rhys Webb, 8 Dan Baker, 7 Sam Underhill, 6 Dan Lydiate, 5 Rory Thornton, 4 James King, 3 Aaron Jarvis, 2 Scott Baldwin, 1 Paul James (c)
Replacements: 16 Sam Parry, 17 Nicky Smith, 18 Dmitri Arhip, 19 Adam Beard, 20 Olly Cracknell, 21 Brendon Leonard, 22 Dan Biggar, 23 Owen Watkin
Scarlets: 15 Steff Evans, 14 Gareth Owen, 13 Regan King, 12 Hadleigh Parkes, 11 DTH van der Merwe, 10 Dan Jones, 9 Gareth Davies, 8 Morgan Allen, 7 James Davies, 6 John Barclay, 5 David Bulbring, 4 Jake Ball, 3 Peter Edwards, 2 Ken Owens (c), 1 Rob Evans
Replacements: 16 Kirby Myhill, 17 Dylan Evans, 18 Samson Lee, 19 Maselino Paulino, 20 Will Boyde, 21 Aled Davies, 22 Aled Thomas, 23 Harry Robinson
Date: Saturday, March 26
Venue: Liberty Stadium
Kick-off: 15:00 GMT
Referee: Ben Whitehouse (WRU)
Assistant Referees: Ian Davies, Wayne Davies (both WRU)
TMO: Jon Mason (WRU)