Former Premier League star Roque Santa Cruz will be leading Olimpia of Paraguay's 40th foray in the Copa Libertadores. Luis Vera/Getty Images

Before the weekend, the 2018 Copa Libertadores will already be over for three of the competing teams.

In the new year-long schedule, introduced in 2017, there are now three qualifying rounds before the group phase kicks off at the end of next month.The first of those rounds features six teams, playing each other home and away, with the first legs on Monday and the return games on Friday.

It is a somewhat strange affair, whose origins lie in the rapid way which the new calendar was organised and announced. Before 2017 the Libertadores was played in the first six months, dragging on until last July during World Cup years. CONMEBOL, South America's administration body, found themselves cash strapped in the wake of the FIFA crisis and looked to rework the schedule. But they failed to consult the clubs before announcing their changes. As a result they lost the participation of the Mexican clubs, who had been invited to take part since the late 90s.

With a cramped domestic calendar of their own, the Mexican clubs could no longer find time to take part in the Libertadores. They pulled out, leaving three extra spaces available for teams from other countries.

Four countries -- Argentina, Brazil, Chile and Colombia -- had already been awarded extra slots in the reorganisation. The solution, then, was to give an extra spot to each of the other six nations: Bolivia, Ecuador, Paraguay, Peru, Uruguay and Venezuela. These teams would then fight it out for a place in next week's second qualifying round.

And so the action kicks off this week with a delightful mixture of the traditional and the new. Macara of Ecuador, from the city of Ambato, in the shadow of the Andes, will be playing their first ever match in the Libertadores. They are one of only three debutantes in this year's competition (the other two, fellow Ecuadorians Delfin and Monagas of Venezuela, are already through to the group phase).

On Monday Macara host Deportivo Tachira of Venezuela, who fell at this stage a year ago. Tachira have played in the Libertadores 21 times. In 2016 they became the only Venezuelan side in the last eight years to make it out of the group phase. They made it as far as the quarterfinals in 2004.

Paraguay's Olimpia will also be playing this week. This is the 40th time that they're competing and have won the whole thing on three occasions. They were in the finals as recently as 2013 and lost during a penalty shootout. Olimpia's squad includes veteran former Premier League striker Roque Santa Cruz, would could be playing in the competition for the last time.

Olimpia's first leg is away to Wanderers of Uruguay, who made it through this stage twelve months ago only to fall in the next qualifying round. Their playmaker, "Nacho" Gonzalez, is another familiar name, a veteran who played for Uruguay in the 2010 World Cup and enjoyed some good seasons in Europe.

The other matchup is between Oriente Petrolero of Bolivia and Universitario of Peru. These teams are not expected to make much of an impact on the tournament.

Oriente Petrolero are from Santa Cruz de la Sierra, a low lying city without the conditions of extreme altitude -- which many visitors to Bolivia find so troublesome. In eight appearances this century they have never come close to making it beyond the group phase. Universitario did reach the final back in 1972, but Peruvian club football was much stronger in those days. The club, who is going through a general decline, also has financial problems. Universitario have also taken part eight times in the current century, only once getting out of the group. They fell in the qualifying round a year ago.

Part of the beauty of the Libertadores, though, is that the danger can come from unexpected quarters. Two years ago, little Independiente del Valle from the outskirts of Quito came through the qualifying round and made it all the way to the final, knocking out River Plate and Boca Juniors along the way, and only losing narrowly to Atletico Nacional in the decider.

They are back again this year -- their fifth consecutive appearance -- and will take on Banfield of Argentina next week in the second qualifying round. Their exploits can give heart to the six teams in action this week. Come Friday night, three of them will still be dreaming.