Estudiantes, San Lorenzo, Nacional must win or face early elimination

Argentina's clubs have put together two good weeks in the Copa Libertadores.

A fortnight ago, their collective record in the group phase made sorry reading: four wins, three draws and seven defeats. Now, those figures look very different: 11 wins, four draws and no addition to that total of seven defeats.

The poor start was entirely predictable. The crisis in the organisation of Argentina's domestic football postponed the start of the domestic season, which got underway a full month later than the original early February kick off. It meant that Argentine clubs went into the Libertadores with little or no competitive games behind them -- and they paid an early price.

The action then paused for World Cup qualifiers towards the end of March, giving the Argentines time to catch up with the rest of the field, and the subsequent results have been much improved. But now, in the case of two clubs from Argentina, the moment of truth has arrived.

Estudiantes, champions in 2009, and San Lorenzo, winners in 2014, still have plenty of work to do to dig themselves out of the hole they fell in after losing their first two matches.

San Lorenzo looked to be on their way out last week when their home game against Chile's Universidad Catolica was tied at 1-1 with five minutes to go. A draw would have left them with two points from four matches, making qualification to the knockout phase dependent on a mathematical miracle. The last throw of the dice was the introduction of Cristian Barrios for his senior debut and, with his first touch, the 18-year-old scored the goal that kept San Lorenzo alive. Even more astonishingly, Barrios, who stands all of 5-ft-2, scored with his head.

The Buenos Aires club, then, won themselves a reprieve, but only until Wednesday when they travel to Brazil to face Atletico Paranaense.

A draw will almost certainly not be good enough, and Atletico are notoriously strong on their artificial pitch in Curitiba. But San Lorenzo are clearly improving -- Wednesday will be a test of just how much.

A day earlier, Estudiantes have their fate on the line in Medellin. This will be their fourth game in the competition. After losing the first two they gave themselves a lifeline by beating Atletico Nacional of Colombia by a single goal in La Plata. Now they meet again at the other end of the continent.

This is a huge game, too for Nacional. They are the reigning champions. But they are finding, as all the other recent winners have done, that success in South American club football is very hard to sustain. Many players have been sold on, and Nacional are in an even worse position than that of Estudiantes, with not a single point from their first three matches.

The only way that they can have the slightest hope of hanging on to their title is by beating the Argentines.

This, then, is likely to be a highly charged occasion. There is just the slightest possibility that both of these sides can make it through to the knockout stage. It is far more likely that both of them fall by the wayside. But maybe one of them can squeeze through.

The knockout games in this year's Libertadores may be more than two months away. But in the case of Atletico Nacional versus Estudiantes on Tuesday night, it is already sudden death.