Copa Libertadores knockouts see South America's interest turn from international to club football

There is help at hand for those suffering from post-tournament withdrawals, and especially for those missing the Brazil-Argentina rivalry of Saturday's Copa America final.

The dial is already turning from international to club football, and starting on Tuesday, the knockout phase gets underway in the Copa Libertadores. Of the 16 teams left standing, Argentina and Brazil have six each; three of them meet home and away this week and next, duelling for a place in the quarterfinals.

Coming into play at this stage are the significant differences in the way that football is organised in the two countries. In Argentina the season roughly follows the European calendar -- the league campaign has yet to kick off. Argentina's clubs have not been in action since the end of May. Since then, contracts have run out, players have been changed clubs and there has not been a single competitive match to bed in the new lineup.

This will surely have an effect on Boca Juniors, who kick off the action on Tuesday at home to Atletico MIneiro. Since making sure of their place in the last 16, Boca have gone through massive changes, losing the iconic figure of Carlos Tevez as well as Mauro Zarate and international goalkeeper Esteban Andrada. Theirs is a new, untried team.

Atletico Mineiro, meanwhile, are a well-oiled machine. After 11 rounds of the Brazilian championship, they lie in third place, and are strengthened by the return of several players from the Copa America: striker Eduardo Vargas (Chile), winger Jefferson Savarino (Venezuela), midfielder Alan Franco (Ecuador) and defender Junior Alonso (Paraguay). The squad is a clear example of the financial power that gives Brazilian football an advantage over its continental rivals. There are also a couple of Argentines, midfielder Matias Zaracho and playmaker Nacho Fernandez, badly missed by his former club River Plate.

The Brazilian clubs have more money, and are in full competitive rhythm, but there may be a point at which fatigue kicks in. All of the other leagues have had some kind of break. In Brazil, though, the 2020 season ran straight into 2021, and players have been in solid activity for a year, with five more months to come.

- Stream ESPN FC Daily on ESPN+ (U.S. only)
- Don't have ESPN? Get instant access

In the group phase Sao Paulo had two tight games with Racing of Argentina. Now they meet again. Sao Paulo have played 11 matches since Racing last took the field, and have shown signs of tiredness in the early stages of the Brazilian championship. Perhaps surprisingly, they have also freed the veteran Dani Alves to play for Brazil in the Olympic Games. Nevertheless, they are probably favourites to get past a Racing side short on inspiration.

The other problem caused by being in permanent activity is the turbulence that frequently hounds Brazilian clubs. Despite winning the league title as recently as February, Rio giants Flamengo have just sacked coach Rogerio Ceni. In comes the charismatic Renato Portaluppi, who took Gremio to the Libertadores title four years ago. His first game in charge is away to Defensa y Justicia of Argentina, a little club who have taken large strides in recent times, and are the reigning champions of the Copa Sudamericana.

Another Brazilian club to have changed coach are Internacional, who have brought in the Uruguayan Diego Aguirre. Results remain disappointing, but Inter are big favourites against Olimpia of Paraguay. There is another Paraguay-Brazil clash when Cerro Porteno take on Fluminense, the only clash involving two teams who have yet to win the Libertadores. In the group phase, both these Paraguayan sides suffered against opposition from Brazil, especially away from home, and they will surely need to dig deep into the legendary reserves of Paraguayan resilience if they are to have a chance of making progress.

The remaining Brazilian side are probably the hottest favourites in the entire round. Reigning champions Palmeiras are top of the domestic league and would seem to have too much for Universidad Catolica of Chile, who are coached by Gus Poyet.

Just two of the eight ties do not feature a team from Brazil. Velez Sarsfield of Argentina are at home to Barcelona of Ecuador in the first leg. Barcelona are the sole remaining team from the north of the continent, and will take heart from the fact that Velez coach, former Southampton boss Mauricio Pellegrino, has his resources depleted. Key playmaker Thiago Almada is with Argentina's Olympic squad, along with left-back Francisco Ortega. And with priority being given to straightening out the club's finances, a number of players have been let go, with Bolivia goalkeeper Carlos Lampe the only significant newcomer. Barcelona will hope to hold Velez in Buenos Aires and tip the balance next week back in Guayaquil.

And even with the problems of ring rust, there is the certainty of one team from Argentina through to the last eight. River Plate take on Argentinos Juniors, who under Gabriel Milito played an impressive and organised brand of football in the group stages. Tournament heavyweights throughout the long reign of Marcelo Gallardo, River have lost Colomba striker Rafael Santos Borre, but replacement Braian Romero looks a good fit. River will expect to qualify, and win time to whip the team into shape to take on the Brazilians a month from now in the quarterfinals.

And there is one more connection with the Copa America. Saturday's final at the Maracana was played in front of 10% of the stadium capacity. It was a hurried last-minute decision that was clumsily executed. Brazil's FA is being fined by the Rio council for the unruly gatherings outside the ground, but it appears to have set a precedent. CONMEBOL have announced that, depending on the approval of the local health authorities, fans will be allowed into the stadiums.