Questions loom over Chile, Argentina in CONMEBOL World Cup qualifying

Ahead of the first stanza of CONMEBOL qualifiers for the 2018 World Cup, ESPN FC's Tim Vickery takes a look at four key questions from the fixtures...

Chile vs. Brazil

Chile have climbed the mountain. Now can they stay there?

Two months ago, after almost a century of waiting, Chile finally had something to put in their trophy cabinet when they won the Copa America on home soil. Will this spur them on to greater triumphs? Or does it represent a high water mark?

The nearest equivalent comes 14 years ago when, also for the first time, Colombia won the Copa at home. At that stage, the 2002 World Cup qualifiers were drawing to a close.

It was widely thought that, emboldened by the conquest, Colombia would surge on to snatch a place in Japan and South Korea. The reverse happened. Colombia's immediate post-Copa results were poor, and they fell just short of the play-off position.

Perhaps there was something predictable in this. It is only natural a team takes its foot off the pedal and eases up in the aftermath of achieving a big objective.

Chile now have to show the same thing will not happen to them. This is the last World Cup cycle for a group of players who have been together since the 2010 qualifiers, and there are few signs of top-class reinforcements arriving in the next generation.

The Chileans begin their campaign against Brazil, a match that produces a clash of styles usually ending up in Brazil's favour. Chile press, commit men forward, and Brazil pick them off on the counter-attack.

Chile have gotten smarter this year as the Copa triumph proves. But a key part of that has been a more defensive deployment of versatile midfielder Charles Aranguiz against the more dangerous opponents. But Aranguiz is now injured. Can Chile reorganise without him? It could be that Arturo Vidal will have to take on more defensive responsibilities.

As far as Brazil are concerned, the question is obvious -- how can they get by with captain and attacking genius Neymar suspended?

Argentina vs. Ecuador

Is this the moment for Carlos Tevez to spark his international career?

There is no Lionel Messi for Argentina. As always in football, the absence of one, however great, is the opportunity for another. Tevez may well not start against Ecuador -- coach Gerardo Martino makes it clear he regards the Boca Juniors star as a centre forward, and that position belongs to Sergio Aguero.

But Tevez is the popular hero, especially now that he has gone back to play his club football at home. Argentina play their home matches at River Plate's stadium, but one end of the ground will be full of Boca fans who, at the first sign of frustration, will be calling for the introduction of their idol. This could create a difficult situation for Martino to administer. He will trust that Angel Di Maria, freed by Messi's absence to switch flanks as he sees fit, will be able to open up the rival defence.

Ecuador coach Gustavo Quinteros, an Argentine by birth, is well aware defence is not his team's strong suit. In the limited time available, he will be drilling his defensive unit in a search for solidity. If he can succeed with that quest, then how much damage can the likes of Antonio Valencia and Jefferson Montero do to Argentina's sluggish back line?

Bolivia vs. Uruguay

Can altitude cover up a multitude of sins?

The previous campaigns always kicked off with the meeting of these two teams in Montevideo with Uruguay usually ahead in the first few minutes and on the way to a convincing victory. Now, though, they meet in La Paz, 3,600 metres above sea level -- Bolivia's not-so-secret weapon.

Bolivia, lately, have given a masterclass in how not to prepare for a World Cup qualification campaign. In the past two months, they have sacked coach Marcelo Soria, unsuccessfully tried to 'unsack' him, appointed Spanish coach Miguel Angel Portugal, seen his appointment blocked by the local clubs, appointed Julio Cesar Baldivieso, lost 7-0 to Argentina and seen two key players (captain and centre-back Ronald Raldes and star centre-forward Marcelo Martins Moreno) make themselves unavailable for selection.

If Thursday's game was in Montevideo, perhaps another heavy defeat was on the cards. But in La Paz, where unacclimatised players lose so much of their athletic capacity in the rarefied air, they still have a chance.

Venezuela vs. Paraguay

Can Salomon Rondon tip the balance in Venezuela's favour?

Venezuela are the only country in South America to never make it to a World Cup. They have made great strides in the past 15 years, but it does look as if they missed their big chance in the previous campaign.

There was an extra space available with Brazil qualifying automatically as hosts, and Venezuela looked at their absolute peak when they beat Argentina early in the campaign. But they fell back and, frankly, do not look as strong this time around.

Key members of the side have aged. Talismanic Juan Arango has just announced his retirement from international football, and the defensive unit also looks increasingly short of pace.

Much, then, depends on the undoubted star man of the current side, centre-forward Salomon Rondon. He is going to have to produce the goods on a regular basis if Venezuela are to make progress. He starts against a Paraguay defence that is not the tallest in the world. Can the imposing Rondon get the better of them in the aerial battles?