South America’s newly crowned champions will begin their quest to make it to the 2018 World Cup on Thursday, when Chile hosts Brazil in Santiago. Chile claimed their first ever senior international title in July when beating Argentina in the final of the Copa America. But as they seek to make it to a third consecutive World Cup, little can be taken for granted in what promises to be the most competitive South American qualification campaign yet.

The fact that Peru and Paraguay made it to the semifinals of the Copa America, and even traditional minnows Bolivia reached the last eight, served to illustrate that there are no longer any weak links in the region. Only four of the 10 teams will make it to Russia automatically, with a fifth going into a playoff against the winners of the Oceania region.

And starting against five-time World Cup winners Brazil, who Chile have not beaten in 14 meetings dating back 15 years, provides a tough baptism. Coach Jorge Sampaoli has also conceded that the squad at his disposal is not as sharp physically as during their emotional run to the Copa America title on home soil.

Of particular concern is the fitness of his two star men -- Alexis Sánchez  and Arturo Vidal. After scoring two goals for Arsenal against Manchester United on Sunday, Sánchez was forced to leave the game early with a groin problem. Ubiquitous midfielder Vidal, meanwhile, only came off the bench for Bayern Munich in their triumph over Borussia Dortmund on Sunday after struggling with a knee complaint.

“Neither is confirmed for the match against Brazil,” Sampaoli said on Wednesday.

While Chile faces a second qualifier in Peru next Tuesday, the importance of Sánchez  and Vidal to Chile could yet see them being named in the starting lineup at the Estadio Nacional on Thursday. Brazil, on the other hand, will definitely be shorn of their star man. Neymar was handed a four-match ban after being sent off for a heated altercation during Brazil’s Copa America group match against Colombia. After the suspension was upheld by the Court of Arbitration for Sport this week, he will miss both the match with Chile and Tuesday’s clash at home to Venezuela.

It provides a real challenge for Brazil’s coach Dunga, who is in need of a strong start to the qualification campaign. Already a far from unanimously popular choice to spearhead Brazil’s recovery from their World Cup calamity on home soil, Dunga fell flat at his first competitive hurdle when suffering Copa America elimination at the quarterfinal stage to Paraguay.

But the former World Cup winning captain has led his country to victory in all 12 of the friendly matches he has overseen. Included in that run was a 1-0 victory over Chile in London this March as well as an impressive 4-1 victory away at the United States last month.

Still, Dunga continues to face questions about his playing philosophy, although he insists he will not be going to the home of the South American champions simply looking to sit back.

"Modern football has shown us, for the good of the game, that only to defend does not work,” he said at his pre-match press conference. "Today, with the quality of the attackers, the ability to shoot from long distance, we have to attack like a boxer. If he is only defending, it is a matter of time before he will get hit. It is the balance between defense and attack."

As well as Neymar, Dunga will also have to attack without Philippe Coutinho. The Liverpool playmaker has pulled out of the squad with injury, leading to a call up for Orlando City’s Kaka.

Kickoff time: 7:30 p.m. EDT

TV channel: beIN Sports

Live stream: beIN Sports Connect