Jamie Roberts will take a step into the unknown on Sunday when the Cardiff Blues travel to west London to face Harlequins in the European Challenge Cup.
For the first time in a decade-long senior career that has yielded myriad individual and team honours, the 29-year-old will come up against one of his former clubs.
The British and Irish Lion admitted "it will feel alien" to play against the team that launched his career, who by a quirk of fate are coached by one of the people who propelled the centre on the path to stardom.
"Danny Wilson was actually my first coach at Rumney RFC," Roberts told ESPN as he pondered his former club's visit to The Stoop. "It will be great to line up against them and play against them rather than playing with them."
Roberts, who lifted the 2010 Challenge Cup with the Blues, added: "It will feel alien. I've never had that opportunity to play against an old club of mine in my career. It will be a first but Cardiff holds very fond memories for me.
"I grew up there, went to university there and the Cardiff Blues and the old Cardiff Rugby Club gave me my first opportunities in rugby and I'm forever grateful for that.
"Guys like Mike Rayer, when he was there, Justin Burnell in the academy, Dai Young as a coach when I first came through -- I'm hugely grateful for the opportunities they gave me to take my first steps on the professional rugby ladder."
The chance afforded him by the Blues all those years ago has certainly been grasped by Roberts, who is now an important member of an upwardly-mobile Harlequins side.
Conor O'Shea's side know anything other than defeat on Sunday will result in a quarterfinal spot for the three-time winners of European club rugby's second competition.
Roberts is a senior figure in a squad brimming with young talent, and predicted a bright future for 22-year-old back-row Jack Clifford, who was handed his first senior England call-up this week.
"I'm not surprised he's in the squad at all," Roberts said. "I think he fully deserves to be -- he's a top lad, quality player, humble in his approach and he's a quality player.
"He's got it all really for his age and certainly one to watch on the international scene."