CHICAGO — So they will meet again. Less than a year after Chile upset Argentina to win the Copa America — the first trophy in La Roja’s history and a second consecutive final defeat for La Albiceleste — the two sides will face each other once again to decide who will be crowned champion of this centenary competition.

Will it be revenge or yet more heartbreak for Argentina? More than likely, the outcome will depend on whether Chile can stop Lionel Messi, at the moment the player of the tournament by some distance.

Messi has recorded five goals and four assists in 254 minutes on the pitch. That’s a direct contribution to a goal every 28 minutes. He has played under the weight of expectation of an American crowd that has demanded brilliance, and he has delivered without fail.

Messi no doubt was key as Argentina reached the World Cup final in 2014 and the Copa final last year, but he was not at his dazzling best during either knockout phase, and was largely kept quiet in both finals. This time, he is playing some of the best football of his career and it would be a genuine surprise if his form dipped at MetLife Stadium on Sunday.

Nobody has managed to suppress him so far. Now it is up to Chile.

The two teams have met twice since July, when Jorge Sampoali’s men held triumphed 4-1 in a penalty shootout. Argentina has won on both occasions, both times by a 2-1 scoreline.

The first of those meetings was in fact the first game as Chile boss for Juan Antonio Pizzi, who took over from Jorge Sampaoli in January. Angel Di Maria and Gabriel Mercado helped Argentina overturn an early deficit to claim victory in their CONMEBOL World Cup qualifiers, but more was to be learned about the new-look Chile in the following months.

La Roja won just one of their next three matches before Copa got underway, including pre-tournament friendly defeats to Jamaica and Mexico. Things were not looking good and they kicked off the defense of their title — against Argentina — looking a shadow of the high-intensity version that had been forged in four years under Sampaoli.

They put up a brave first-half fight against Tata Martino’s men in Santa Clara, California, at the start of this month but were undone by Di Maria, who took center stage in the absence of the injured Messi.

But while Messi was to come back with a bang in his next game — with a stunning hat trick in Chicago — Chile continued to struggle. A victory over Bolivia, secured thanks to a controversial penalty in the 100th minute, and a topsy-turvy 4-2 win against Panama sealed passage into the knockout round. Still they looked miles from their best.

Then everything changed. "That game they exploded," Colombia coach Jose Pekerman said of Chile’s 7-0 thrashing of Mexico, the best team performance of the tournament so far and probably one of the best in international football for some time. That set up a semifinal with Colombia, and Pekerman’s men found themselves on the end of another explosion.

Chile was 2-0 up within 11 minutes, overloading the right-hand side and piling through the Colombians at will. Shorn of Arturo Vidal through suspension and Marcelo Diaz through injury, the champions were supposed to struggle. Not a chance. It was only until Pedro Pablo Hernandez, the third-choice midfield reinforcement, went off injured that Colombia managed to get a foothold in the match. But still they could not find a way through, even if they should have had a penalty just moments into the second half following a delay of more than two hours thanks to stormy conditions at Soldier Field.

There is no doubt that Chile has grown into this tournament and will face Argentina fully confident that it can inflict yet more suffering. Pizzi's men are better placed than any other team in the competition to do so.

Martino certainly rates them, too. Ahead of his side’s semifinal with the U.S., he was asked to rate Jurgen Klinsmann’s men. He reckoned they were the second best team they would face this summer, behind La Roja: “You know what I think about Chile,” he said. They have earned their place as one of the planet's top soccer nations over the past few years.

But can they stop Messi? With Vidal back at the heart of their relentless midfield pressing machine, which completely nullified Colombia before Hernandez’s exit here, Argentina will face its toughest test since, well, its opening game of this tournament.

With Messi consigned to the bench through injury, Chile lacked craft up front to take advantage of its chances, even when presented with clear sights of goal thanks to Argentina’s sloppiness at the back.

Martino has acknowledged his concern about his side’s deficiencies repeatedly over the past week, and although Argentina was never close to being exploited against the U.S., he will no doubt put his players through their paces on the training pitch ahead of the final.

Martino has cited his team’s buildup play as one area in need of improvement, meaning Chile’s high press is certainly going to cause issues. La Roja's hard work in midfield will also make life hard for Messi, but as Di Maria showed at Levi’s Stadium, quality players can still make the difference. 

And right now there is nobody with more quality than Messi. Chile has done it before, and if everything goes its way this side can do it again. But, with the No. 10 in this form, Argentina deserves its tag as the favorite.