Isgro has achieved three touchdowns in three appearances at this renowned venue, facing Premiership rivals in Quins' annual 'big' fixtures and South Africa in a moved Rugby Championship game.
Quilter Nations Series: The Pumas vs England
Stadium: The Allianz Stadium at Twickenham Match Day: This coming Sunday, November 23 Start Time: 16:10 Greenwich Mean Time
Coverage: Available on BBC Sounds and Radio 5 Sports Extra with real-time text updates on BBC Sport's digital platforms.
From the shadow of the Andes to the shadow of the Allianz Stadium constitutes a travel of roughly 11,000 kilometers.
And last autumn, Isgro sensed each mile.
Displaying a conquistador moustache and thighs as thick as a gaucho's steak, he faced significant cultural differences when the Argentina wing arrived at Harlequins.
This involved more than an unfamiliar country, a new club and a different tongue, but also a new game of rugby.
"During the last half-decade my focus was sevens rugby and I came to England with just a couple of games of traditional rugby," remembers Isgro.
At twenty-six years old was a short-format star - the Olympic rings tattooed on the inner part of his right arm are a memento of a bronze medal achievement in the Tokyo Games.
In 2023, he received recognition as the world's best sevens player.
The player could have continued in the shorter format and enjoyed a globe-trotting circuit with well-known colleagues.
But, following his selection into Argentina's traditional rugby team by then-Argentina coach Michael Cheika for last year's World Cup, he made the full transition by signing for Quins in the next season.
He competed as part of the Argentina sevens side that secured the bronze medal at the Olympic Games in Tokyo in two years ago.
London represented the location for his initial international journey, a participation at the glamorous though brief Rugby X tournament at the O2 Arena in the year 2019.
Getting used to everyday existence in Guildford, his new home was difficult nevertheless.
But it would have been even harder without his team-mates - and a specific individual.
"The fly-half represents a close friend," adds Isgro, born in Mendoza.
"His support was invaluable during my arrival in England. He dedicated considerable time to me, as well as tolerance and comprehension.
"My English was not very good - I didn't speak it. He's an outstanding companion, he drinks 'mate' with me every day."
Along with the traditional South American herbal drink - preferred by soccer great Lionel Messi - England fly-half Smith would share lifts into training with Isgro.
They connected effectively on the pitch too.
A quarter of an hour into Isgro's debut against the Bath team, Smith cut blind, kicked across the pitch and the winger claimed the ball over the head of his opposite number for a score.
Isgro scored another in the first half and emerged as a popular figure at Harlequins' home ground subsequently, extending his contract in the winter month.
"The adjustment challenged me because the language is different but I developed considerably, both with my personality and in rugby," he states.
"It was a really good challenge and now I feel really good. I felt nervous initially, and currently I'm pleased that I'm settled here."
Isgro crosses for a debut try for Quins in last October.
During the weekend, the teammates will be competing against each other from their home ground and facing one another when the international rivals compete at Twickenham's stadium in the final match of their fall series.
And Isgro is at the head a pack of Prem Pumas hunting the hosts.
Gonzalez is at the Premiership side, the Bath player at Bath Rugby, Simon Benitez Cruz recently signed with the Falcons, while Rubiolo and Grondona are at the West Country club.
Petti, Delgado and Wenger have all come to Harlequins in the current term.
"We frequently gather," says Isgro. "One or two times a week.
"[Former London Irish hooker] Agustin Creevy makes his home in Kingston and we gather at his house for a grill session.
"Gonzalez and injured colleague Cinti reside in North London. The Argentine Quins contingent are based in the south, in Guildford, and we gather at Creevy's home."
There have been many experiences to reflect upon, along with the barbecue.
The Pumas beat England during their previous encounter at Twickenham in 2022 and since then have overcome South Africa, the All Blacks, France and Australia, along with upsetting the Lions' inaugural match in Dublin in the summer with a 28-24 victory.
Does Isgro believe Argentina - ranked sixth in the world are being underestimated by English supporters that has seen their team rack up an unbroken winning streak and {beat the All Blacks|defeat New Zealand|overcome the All Blacks
