Smith’s selection is one of eight changes made by the coach to his starting side for the deciding match of the series. There is also a new captain, with Hamish Watson taking the reins from Grant Gilchrist who is being rested for the final match of the tour.
Smith has already impressed in South America, playing in the the A team's victory over Chile in Santiago. He now gets the opportunity to win his first full cap, reward for a strong end to the season with his club.
“We’ve got high expectations of Ollie because of the way he’s been training and playing this year for Glasgow,” said Townsend. “That suggests he’ll transfer that form into the Test match arena.”
Smith has had to show maturity beyond his 21 years following the loss of his older brother, Patrick, in a tragic accident in 2019 when he fell from a third-floor window at a house party in Edinburgh and was pronounced dead at the scene.
His family launched the Give Blood 4 Good charity in memory of Patrick, and Ollie and his sister Hanna have been involved in encouraging hundreds of people to donate blood.
The strength of character shown by the full-back has not gone unnoticed by Townsend who suggested he was ready to play him in the third Test regardless of the injury sustained by Rory Hutchinson who was at 15 for the opening two matches against Argentina.
“I think he’s shown this year on the playing field his proactive nature,” said the Scotland coach. “The way he plays, he takes the game to the opposition with ball in hand, he’s an aggressive defender. He’s a young player too. He was part of that under-20s group from two seasons ago, along with Rory Darge, Ewan Ashman, Rufus McLean.
“So there’s a big future ahead of him and we’ve been really impressed with what he’s done over the last 12 months.”
Hutchinson wasn’t the only player injured in last weekend’s 29-6 win in Salta; Kyle Rowe sustained a serious knee problem and Darcy Graham suffered a concussion. Their absence opens the door for Rufus McLean to win his third cap on the wing.
There are also changes at inside centre, where Sione Tuipulotu replaces his benched Glasgow team-mate Sam Johnson, and at scrum-half, where Ali Price comes in for Ben White, who is unlucky to drop out.
There are also four changes in the pack for the match at Santiago del Estero, a city 1,000km northwest of Buenos Aires.
Ewan Ashman is selected at hooker for his first start for Scotland as Dave Cherry drops to the bench.
Rory Sutherland, the Worcester loosehead prop, comes in for Pierre Schoeman who is among the substitutes. There is a new combination in the second row where Scott Cummings and Jonny Gray take over from Sam Skinner and Gilchrist.
The back row of Rory Darge, Watson and Matt Fagerson which so impressed last week remains in place, as does Blair Kinghorn at stand-off.
Glen Young, the Edinburgh lock, could make his Scotland debut after being named on the bench.