Rory Lamont will make his Scotland debut alongside brother, Sean, in the RBS 6 Nations game against Wales on Sunday.
Scotland coach Matt Williams has drafted in Glasgow Warriors' Rory, 22, in place of Simon Webster as the Lamonts become the 19th pair of brothers to play together for the Scots.
The introduction of Lamont for his first cap is the only change to the Scotland side which defeated Italy at Murrayfield two weeks ago.
Williams denied he was taking a chance giving the younger Lamont brother his debut against a confident Welsh side, overwhelming favourites to carry on their unbeaten run in this season's RBS 6 Nations Championship.
He said: "If you're good enough, you're old enough.
"Since I've been here I've given around 12 players their opportunity and 12 months ago nobody had heard of Chris Cusiter and Allister Hogg, but look where they are now.
"We wouldn't be giving Rory the opportunity if we didn't have the evidence that he could handle it.
"We've been lucky for players to break the line and be aggressive with a good kicking game and strong running.
"And obviously we haven't been happy with all the performances recently.
"Rory is a young player we've been watching this season and we are impressed with what we've seen.
"We've had him in the squad from the beginning of the Six Nations tournament and we just felt it was time for him to step up and take his opportunity.
"We're fortunate to have someone like Rory, and his brother Sean, with their physique, power and pace.
"The roll of winger and fullback has changed dramatically in the last five or six years and our opponents, Wales in particular, all have a strong kicking game.
"So you need powerful and skilful players and Rory will have his chance to show what he can do."
The Scotland team to play Wales in the RBS 6 Nations Championship on Sunday 13 March:
C Paterson (Edinburgh Rugby); R Lamont (Glasgow Rugby), A Craig (Glasgow Rugby), H Southwell (Edinburgh Rugby), S Lamont (Glasgow Rugby); D Parks (Glasgow Rugby), C Cusiter (The Borders), T Smith (Northampton Saints), G Bulloch (Glasgow Rugby), G Kerr (Leeds Tykes), S Grimes (Newcastle Falcons), S Murray (Edinburgh Rugby), S Taylor (Edinburgh Rugby), A Hogg (Edinburgh Rugby), J Petrie (Glasgow Rugby)
Replacements: R Russell (London Irish), B Douglas (The Borders), N Hines (Edinburgh Rugby), J Dunbar (Leeds Tykes), M Blair (Edinburgh Rugby), G Ross (Leeds Tykes), A Henderson (Glasgow Rugby)
England flanker James Haskell insists he will be pushing as hard as possible to be back from a toe injury in time to make his case for a spot in Eddie Jones' side looking to defend their RBS 6 Nations title next year.