The giant lock will take on Wales today at BT Murrayfield, leaving the Warriors to prepare for their match away to Zebre without him.
Fellow lock Al Kellock will captain Gregor Townsend's side on his 150th appearance for the Warriors, and while Gray is full of admiration for his club-mate, he inevitably finds himself looking up to another second row even closer to home.
"I've been very lucky to work with Al," he told the Scottish Daily Mail. "He's great to sit down and talk with, share his experiences at line-outs and other areas.
"But my brother Richie is the biggest role model I've had growing up. It's just great to have a guy like that by my side.
"Growing up watching him, I've been lucky to have him there and to see first-hand how hard he had to work to get where he is.
"His diet, his extras, his training - for me to see that first-hand, there were no excuses for me."
Richie, at 25 now a veteran in the Scottish team, spent his formative years with the Warriors before moving to Sale Sharks and now Castres.
Jonny, not even 21 for another month, will lock down alongside his brother as Scotland look to build on an impressive start to new head coach Vern Cotter's reign.
And he is fully aware of the challenges faced when stepping from GUINNESS PRO12 rugby into the international arena.
"The team spirit here in the Scottish camp is very strong," he added. "We go into every game thinking we can win. But we know how tough it's going to be.
"It's going to be a massive challenge, so we need to make sure we get our preparations just right."
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