Going into only the fourth week of action in the group phase of this year’s Copa Libertadores, a host of title hopefuls are already finding the going harder than expected. Indeed, among those in dire need of three points are previous Libertadores winners such as Colo Colo, Penarol, Nacional de Montevideo, Once Caldas and Liga Deportiva Universitaria de Quito, as well as Mexican heavyweights America and Brazilian champions Fluminense.

FIFA.com takes a look at the pick of the encounters ahead, including two featuring only former champions: Nacional-Argentinos Juniors and Liga de Quito-Independiente.

Game of the week   
Liga de Quito (ECU) - Independiente (ARG)
Group 8, Thursday 3 March, Estadio Casa Blanca (Quito), 20.30 (local time)   

The Ecuadorian outfit, Libertadores winners in 2008 and Copa Sudamericana victors in 2009, host seven-time continental champions Independiente of Argentina in a repeat of the Sudamericana 2010 semi-final. Though LDU Quito won the first leg 3-2 on that occasion, El Diablo Rojo turned the tables in the return game before downing Brazil’s Goias in the final. Beaten 2-1 away to Godoy Cruz in their opening group game two weeks ago, coach Edgardo Bauza’s Ecuadorian league leaders will be aiming to bounce back on Thursday on home soil. Independiente, for their part, put their struggles in the domestic Clausura to one side when posting an emphatic 3-0 opening home win over Penarol.

In Group 1, Colombia’s Once Caldas, winners in 2004, have picked up just a point from their opening two games and will be hoping for a win at the third attempt away to Mexico’s San Luis. Yet the home side are on even shakier ground having lost both their encounters so far and can scarcely afford any more slip-ups themselves.

Over in Group 8, five-time champions Penarol return to Argentina looking to set the record straight after their comprehensive defeat at Independiente. Opponents Godoy Cruz, under Uruguayan coach Jorge Da Silva, kicked off their debut Libertadores campaign by beating LDU Quito at home, and fans of El Expreso would love to see their heroes take another notable scalp.

Montevideo side Nacional, continental champions on three occasions, have only one point in the bag from two Group 3 games thus far. Up next for them are section leaders Argentinos Juniors, Libertadores top dogs in 1985. Staying in this section, Fluminense travel to Mexico’s mythical Estadio Azteca to take on America without first-choice strikers Fred and Emerson. Flu were held to home draws in their first two games while Las Águilas beat Nacional and lost to Argentinos Juniors.

Turning to Group 4, leaders Velez Sarsfield are aiming to follow up their 3-0 opening win over Caracas with a second success against Chile’s Universidad Catolica. Caracas, for their part, welcome another Chilean outfit, Union Espanola, to the Venezuelan capital.

Group 5 is notable for Argentinian supremo Americo Gallego’s debut as coach of Chile’s Colo Colo. His first task is to help El Cacique bounce back from their opening humbling by Cerro Porteno when visiting Venezuela’s Deportivo Tachira. Group 7 fast-starters Cruzeiro, fresh from two emphatic home wins, will be put to the test at Colombia’s Deportes Tolima, who are three points behind in second.

Finally we turn to Group 2 and Porto Alegre side Gremio, who were beaten 2-1 at Colombian outfit Junior last time out. Next up for O Tricolor da Azenha are Peru’s Leon de Huanuco, level on three points with Gremio after victory over Bolivia’s Oriente Petrolero.

Player to watch
Wallyson (Cruzeiro)
A July 2010 signing from Atletico Paranaense, the 22-year-old striker is clearly finding his feet at A Raposa. Four Libertadores goals already is testament to that, a tally that keeps him atop the competition’s scorers’ charts alongside Cerro Porteno’s Argentinian forward Roberto Nanni.

The stat
22 –
The number of months Liga de Quito have gone without losing at home in continental competition, a run which stretches back to a 3-2 Libertadores group-stage defeat by Sport Recife on 29 April 2009.

What they said
“We mustn’t be over-confident just because they (Colo Colo) were thrashed in their opening game. They’ve got good players who’ll want to prove their worth in front of (Americo) Gallego. This game will indicate how far we can go in this Copa,” Deportivo Tachira midfielder Pedro Fernandez, ahead of Tuesday’s meeting with El Cacique.

Tuesday 1 March
Deportivo Tachira (VEN) – Colo Colo (CHI)
Godoy Cruz (ARG) – Penarol (URU)

Wednesday 2 March
San Luis (MEX) – Once Caldas (COL)
Nacional (URU) – Argentinos Juniors (ARG)
America (MEX) – Fluminense (BRA)
Deportes Tolima (COL) – Cruzeiro (BRA)

Thursday 3 March
Gremio (BRA) – Leon de Huanuco (PER)
Caracas (VEN) – Union Espanola (CHI)
Velez Sarsfield (ARG) – Universidad Catolica (CHI)
Liga de Quito (ECU) – Independiente (ARG)