Alex Blair will make his Edinburgh debut in place of his brother, David, during Saturday's Magners League clash against Leinster.
The stand-off will line up alongside another elder brother, Mike, after the scrum-half overcame the bug that kept him out of last weekend's victory over Ulster.
David Blair has failed to recover from a head blow sustained in training to allow his younger brother to start, fresh from his travels to India with Scotland's Commonwealth Games sevens team.
Scotland A international Alex, who stepped up to the professional ranks from Edinburgh Accies in the summer said: "I've been working hard to earn this opportunity, and I'm really grateful to the coaches for having shown this level of faith in me.
"Dave's been playing really well recently, so it's unlucky for him that he needs to miss out this weekend, but you've got to grasp your chances as and when they come, and I'll certainly be aiming to make the most of this one.
"It will be good to have Mike beside me at half-back, not just because he's my brother, but because he's a hugely experienced player who'll be able to give me a few pointers when he feels it's required.
"It's a big game to be making my debut in, but I'm relishing the thought of going to a place like the RDS and showing what we're all about.
"As a team, we're all really keen to keep this good run going and add to the momentum that's been building."
Head coach Rob Moffat has made four more changes to his starting line-up as Ross Ford and Roddy Grant return after being rested against Ulster.
John Houston and Alex Grove will form a new centre pairing after James King dropped out with a knee injury.