Edinburgh coach Alan Solomons has handed scrum-half Sam Hidlago-Clyne his first start against Scarlets at Murrayfield Stadium on Friday.
With captain Greig Laidlaw out injured (knee), 20-year-old Hidalgo-Clyne has forced his way on to the bench in every match so far this season, with 22-year-old Sean Kennedy getting the nod to start until this week.
Solomons, got his first sight of Hidalgo-Clyne on the club's pre-season camp at Loughborough University, and has been impressed with his contribution so far.
"We're quite fortunate in that, despite losing a key international player, we have two very talented young Scottish scrum-halves in Sam [Hidalgo-Clyne] and Sean [Kennedy], who are pushing each other very hard for the chance to start each week," said Solomons.
"Sam now deservedly gets this opportunity after five appearances off the bench.
"They're both still very young but are in excellent condition and show a lot of promise, which is great news for the club."
Hidalgo-Clyne's selection is one of four personnel changes to the backline, with centre Ben Atiga returning in place of the injured Dougie Fife (head knock).
Lee Jones starts in place of injured wing Tim Visser (head knock), while fellow Scotland internationalist, Jack Cuthbert, is selected in place of Nikki Walker.
The return of rotated front-row forwards Ross Ford (hooker) and Willem Nel (prop) are the only changes to the pack, while Argentine trialist Joaquin Dominguez could make his debut if called upon from the bench.
"Scarlets are another consistently impressive Welsh side, so will present another big challenge tomorrow night," added Solomons.
"Like us, they haven't had the kind of start they would have wanted and, having won in Edinburgh last year, will look at this match as an opportunity to put their campaign back on track.
"It's up us to front up to that challenge. We're playing at home in front of our own fans, so it's important that we go out there and deliver a vastly improved performance."
Meanwhile, Scarlets coach Simon Easterby has made five changes to the side that went down 23-16 to the Dragons last week.
Aaron Shingler's neck injury rules him out of the Murrayfield fixture, and he is replaced by Josh Turnbull at blindside flanker.
Hooker Ken Owens drops to the bench, making way for Emyr Phillips, and John Synman takes the place of George Earle in the second row, who is also named among the replacements.
At scrum-half, fit again Rhodri Williams comes in for Gareth Davies, and Gareth Maule is set to make his first appearance of the season from the bench, having damaged knee ligaments during pre-season.
Full-back Gareth Owen picked up a knee injury during the Dragons defeat, seeing Liam Williams switch from right wing to the number fifteen jersey. Nick Reynolds comes in to fill the wing position vacated by Williams. Steve Shingler has yet to recover from the ankle injury that kept him out of last week's clash.
"We are expecting Edinburgh to be very competitive back at home this weekend. They have key individuals in their team that we'll have to manage and will be well-organised under an experienced coach in Alan Solomons," said head coach Simon Easterby.
"They have players up front that give them good go forward as well as the threats on the wing. It'll be about imposing our game plan and stopping them from getting their game going.
"Both sides are looking to get some form, so hopefully it will be an entertaining fixture like last week and this time we'll be working hard to come back with the right result this time."
Form: Edinburgh Rugby's last five matches have all been won by the home side on the day, whilst their only defeat at Murrayfield since February was 24-32 to Connacht in April. Scarlets only win in their last five RaboDirect Pro12 encounters was 26-10 at home to Treviso in round 2. The Welshmen have won their last four encounters against Scottish opponents. Edinburgh have beaten Scarlets just once in their last six fixtures since 2010: 26-23 at Murrayfield in March 2012. Welsh Regions have been victorious on three of their last four visits to Murrayfield.
Edinburgh: 15 Greg Tonks, 14 Lee Jones, 13 Nick De Luca, 12 Ben Atiga,11 Jack Cuthbert, 10 Harry Leonard, 9 Sam Hidalgo-Clyne, 8 David Denton, 7 Roddy Grant, 6 Dimitri Basilaia, 5 Izak Van der Westhuizen, 4 Grant Gilchrist, 3 Willem Nel, 2 Ross Ford (c), 1 Alasdair Dickinson.
Replacements: 16 James Hilterbrand, 17 Wicus Blaauw, 18 Geoff Cross, 19 Sean Cox, 20 Hamish Watson, 21 Sean Kennedy, 22 Joaquin Dominguez, 23 Michael Tait.
Scarlets: 15 Liam Williams, 14 Nick Reynolds, 13 Jonathan Davies, 12 Scott Williams, 11 Jordan Williams, 10 Rhys Priestland, 9 Rhodri Williams, 8 Rob McCusker (c), 7 John Barclay, 6 Josh Turnbull, 5 John Snyman, 4 Jake Ball, 3 Samson Lee, 2 Emyr Phillips, 1 Phil John.
Replacements: 16 Ken Owens, 17 Rob Evans, 18 Jacobie Adriaanse, 19 George Earle, 20 Sione Timani, 21 Aled Davies, 22 Aled Thomas, 23 Gareth Maule.
Date: Friday, September 27
Venue: Murrayfield Stadium
Kick-off: 19:45 BST
Referee: David Wilkinson (Ireland)
Assistant Referees: Peter Allan (Scotland), Adrian Graves (Scotland)