But you would have doubted them. None were in much of a state of mind to entertain the idea that, come July, they could be 90 minutes away from contesting the championship of their continent.

Guerrero, who turned 35 in January, had not played any competitive football since the previous summer when he scored his 35th goal for his country in the last match of their only adventure at a World Cup finals during his lifetime.

Guerrero had only been allowed to play in Russia, where Peru were eliminated at the group stage, at the last moment, a controversial doping ban having been temporarily lifted on appeal.

The suspension then resumed in August and kept him from playing for his country or for his Brazilian club, Internacional, until the following April.

Vargas, meanwhile, all but assumed his international career, one that had extended to 78 caps and included a starring spearhead role in Chile’s successive Copa America victories of 2015 and the Centenario edition of 2016, was over.

Since Chile had appointed the worldly Colombian Reinaldo Reina as manager, Vargas, 29, had heard only frosty messages from the new boss. He had not been called up for the national squad for a year, despite netting goals regularly for his Mexican club Tigres.

As for Sanchez, 30, where to begin? For the former dazzling dynamo of Chile’s so-called golden generation, the decline in the period since he moved from Arsenal to Manchester United in the new year of 2018 has become an unfathomable saga.

By March it was reaching a nadir: he was drawing the highest salary at English football’s most fabled club and yet he reached the last stage of United’s fractured season used more often from the bench than the starting XI, and was even further marginalised by hamstring and knee injuries.

Fast forward to this July in Brazil, and this tortured trio have been revitalised. Ahead of Wednesday night’s Copa semi-final between Chile and Peru in Porto Alegre, Vargas has scored two of Chile’s six goals in the tournament, a pair of strikes notable for the sweet timing of boot on ball. He does not look like a man out of sync with his national team, though he was only recalled after his long absence by Rueda last month.

Sanchez has scored twice, too – that is as many goals as he registered for United across all competitions last season. Against Japan in the opening 4-0 win by the defending champions, he thumped in a diving header and, in the 2-1 win over Ecuador, an elegant half-volley, from some 15 yards out.

These were not the work of the Sanchez who has been wandering, chaotically, into the wrong spaces for much of his time on the pitch with United. These were confident, purposeful interventions.

“He feels happy in this environment,” says Rueda, who watched Sanchez clinch the quarter-final by converting the last penalty in a perfect round of Chilean spot-kicks after a 0-0 draw over 90 minutes against Colombia. Vargas had converted the second.

Earlier that day Guerrero put Peru ahead in the shoot-out that resolved their deadlocked quarter-final against Uruguay, on his 91st cap for his country.

Guerrero’s 36th international goal, meanwhile, had launched the comeback from 1-0 down against Bolivia in the second group match. It finished 3-1, and took Peru to the four points they needed to come out of their group.

With their goals in Brazil, Vargas and Guerrero, on 12 each, are jousting to be the leading scorers, among players still active, in the history of Copa America final tournaments. That’s one duel to enliven Wednesday night’s contest.

There is also a fresh grudge to the so-called ‘Pacific Clasico’. Chileans recall the events of late 2017, when Peru snatched the last of South America’s qualifying places for the Russia World Cup, and Chile were left shy by narrow goal difference on the last day of the round-robin. Peru and Colombia had drawn their match 1-1, a result that maintained both teams in positions above Chile.

The game is now notorious, dubbed by Chileans as the ‘Lima Pact’. Some Peru players later acknowledged that in the final moments of their fixture, there had been whispered suggestions passed between rival Peruvian and Colombian players that they could all ease up, knowing that, with a draw, neither could be caught up by Chile.