Sam Davies will make his Heineken Cup debut at full-back for Ospreys in Friday's clash against Castres at Liberty Stadium.
Ospreys' hopes of making the play-offs are all but over following the 15-9 defeat in France last week when the Welsh region slipped to a third straight loss in Pool 1 though they will take encouragement from their losing bonus point.
Toulouse are the only French side to have triumphed at the Liberty Stadium back in 2004 and Castres are among the long list of losing Top 14 teams having been seen off 20-11 at the same venue in January 2005.
"It was a tough evening out in Castres last weekend and although we were obviously disappointed to come away with just a point, there was a lot of good that we could take out of the game and use to prepare for Friday night," said Ospreys Head Coach Steve Tandy.
"The circumstances going into the game were obviously very difficult but it was pleasing to see a young and pretty inexperienced team pushing the French champions to the limit. The commitment, defensive effort and the resilience shown was first rate to keep us in the game and we very nearly pinched it at the end. The game is all about fine margins and we were unfortunately unable to snatch the win, but what we saw in France will give us real confidence going into the return.
"Going into these games on the back of four tough, physical, autumn internationals, straight into two Heineken Cup games, three Welsh derbies and then Europe again in January, it's a big ask for certain players to go right through. We don't have the strength in depth that we used to, none of the regions do, which means that we have to manage players to ensure that they are physically able to cope with the workload.
"That was why Richard Hibbard started on the bench last weekend, and why Alun Wyn will sit out Friday night. We need to ensure that we have these boys available for the longer haul. The flipside of this is that we get some valuable game time for boys coming through the squad.
"We had a great afternoon here at the Liberty 12 months ago in similar circumstances against Toulouse and that will be the target on Friday night. With big Welsh derbies coming up it's important that we get things right on the field, and build some momentum with some good performances in front of what we hope will be some big crowds, not only on Friday but against the Scarlets and Northampton next month."
Marc Thomas will make his Heineken Cup debut if he comes off the bench.
Castres have made two changes to their backline with Geoffrey Palis taking over from French international Brice Dulin at full-back while Remi Tales returns to the fly-half berth as Daniel Kirkpatrick drops to the bench.
In the pack, there is an all-new back row including Antonie Claassen at number eight, Rodrigo Capo Ortega comes into the second row ahead of Christophe Samson and there are also two new props as Yannick Forestier returns.
Ospreys: 15 Sam Davies, 14 Aisea Natoga, 13 Tom Isaacs, 12 Ben John, 11 Jeff Hassler, 10 Dan Biggar, 9 Rhys Webb , 8 Ryan Jones (c), 7 Justin Tipuric, 6 Sam Lewis, 5 James King, 4 Ian Evans, 3 Aaron Jarvis, 2 Richard Hibbard, 1 Ryan Bevington.
Replacements: 16 Scott Baldwin, 17 Marc Thomas, 18 Dan Suter, 19 Tyler Ardron , 20 Morgan Allen, 21 Tom Habberfield, 22 Matthew Morgan, 23 Tom Grabham.
Castres: 15 Geoffrey Palis, 14 Marcel Garvey, 13 Remi Lamerat, 12 Paul Bonnefond, 11 Remi Grosso, 10 Remi Tales (c), 9 Rory Kockott, 8 Antonie Claassen 7 Yannick Caballero, 6 Jannie Bornman, 5 Rodrigo Capo Ortega, 4 Richie Gray, 3 Anton Peikrishvili, 2 Marc-Antoine Rallier, 1 Yannick Forestier.
Replacements: 16 Brice Mach, 17 Saimone Taumoepeau, 18 Michael Coetzee, 19 Christophe Samson, 20 Ibrahim Diarra, 21 Julien Tomas, 22 Daniel Kirkpatrick, 23 Max Evans,
Date:Friday 13th December
Venue: Liberty Stadium
Kick-off: 2000 (local & GMT)
Referee: Luke Pearce (England)
Assistant referees: Dean Richards, Robin Goodliffe (both England)
TMO: Geoff Warren