The Ospreys have named Matthew Morgan at fly-half in place of fellow youngster Sam Davies for their LV= Cup clash with Cardiff Blues on Friday.
The change at 10 is one of many made by head coach Steve Tandy, with Morgan lining up alongside Italian scrum-half Tito Tebaldi.
Joe Bearman comes in at number eight while Jamie Murphy, Aisea Natoga, Jonathan Spratt, Dafydd Howells and Dan Suter also make the XV.
"We're really excited by the opportunity Friday to play a local derby at home in the Liberty Stadium in front of our fans and I hope that they can come out to support us," said backs coach Gruff Rees.
"We've had some great battles with the Blues over the last few years and we want who ever puts the shirt on to do it justice.
"There's some good history in the derby in the Ospreys jersey but for me a good derby is also based on local derbies such as Swansea v Cardiff or Neath v Cardiff.
"I hope these players realise that they're on the apex of pro rugby and that they can start to make a name for themselves in these kind of games."
Cardiff Blues meanwhile will be looking to bounce back from their 21-16 loss to Worcester.
Fly-half Simon Humberstone makes his first ever start for the region after impressing off the bench last week and joins forces with Alex Walker at half-back. Centre Gavin Evans starts.
Prop Sam Hobbs is called up at loosehead while flanker Ellis Jenkins and number eight Robin Copeland are also named in the forward pack for the game at Liberty Stadium.
Cardiff Blues are currently without 20 players for the game, such as Josh Navidi, Andries Pretorius, Marc Breeze, Ben Roach, Harry Robinson, Rhys Patchell, Gareth Davies.
Ospreys: 15 Jamie Murphy, 14 Aisea Natoga, 13 Tom Isaacs, 12 Jonathan Spratt (c), 11 Dafydd Howells, 10 Matthew Morgan, 9 Tito Tebaldi, 8 Joe Bearman, 7 Arthur Ellis, 6 Graham Knoop, 5 Rhodri Hughes, 4 Lloyd Peers, 3 Dan Suter, 2 Matthew Dwyer, 1 Marc Thomas.
Replacements: 16 Evan Yardley, 17 Nicky Smith, 18 Nicky Thomas, 19 Sam Williams, 20 Sam Lewis, 21 Rhys Webb, 22 Sam Davies, 23 Ben John.
Cardiff Blues: 15 Dan Fish, 14 Richard Smith, 13 Gavin Evans, 12 Dafydd Hewitt, 11 Chris Czekaj, 10 Simon Humberstone, 9 Alex Walker, 8 Robin Copeland, 7 Thomas Young, 6 Ellis Jenkins, 5 James Down, 4 Macauley Cook, 3 Benoit Bourrust, 2 Kristian Dacey, 1 Sam Hobbs.
Replacements: 16 Rhys Williams, 17 Taufa'ao Filise, 18 Tom Davies, 19 Miles Normandale, 20 Rory Watts-Jones, 21 Luke Hamilton, 22 Lewis Jones, 23 Tom Williams.
Date: Friday, November 15
Kick-off: 19:30 GMT
Venue: Liberty Stadium
Referee: Greg Macdonald (England)
Assistant referees: Jon Mason (Wales), Ben Whitehouse (Wales)