By NESTOR F. SEBASTIAN

The Copa Libertadores Round of 16 phase got underway on Tuesday with an all-Brazilian affair that jumpstarted the home and away legs in all matches for the next two weeks. With the swine flu scare still hovering, both Mexican teams involved in this round could possibly host their ties here in the U.S. with reports in South America naming Chicago and L.A. as potential spots. Ecuador and Brazil have also offered their stadiums to the Mexicans, who were scheduled to host their first-leg tilts tonight.

Another match postponed as well was the Defensor Sporting-Boca Juniors scheduled for Thursday at the infamous Centenario Stadium in Uruguay. A concert involving a local band in that country is due to take place there on Thursday, pushing the Libertadores tilt to next week.

Here is an update to Libertadores action this week, which will be on Fox Sports en Espanol:

TUESDAY

At the Palestra Italia, Palmeiras was backed by a raucous 25,000-strong crowd and walked away with a slim 1-0 win over compatriots Sport Recife with a goal by Paraguayan Jose Maria Ortigoza in the 75th minute, just 10 minutes after coming on.

Sport, however, is breathing a sigh of relief because they went down a man shortly before the goal and Palmeiras wasted several chances on increasing their lead, including a 90th minute header that hit the post.

WEDNESDAY

8:50PM ET
Peru's San Martin is the lowest-seeded team in the tournament, meaning that they will face the top side, Brazil's Gremio. The Peruvian squad is a modest side that's been in existence for just about five years and now hosts one of the South American giants in their backyard tonight in Lima. Everyone is giving San Martin very little chance and anything other than a loss for the Peru squad would be a surprise.

THURSDAY

4:20PM ET
Ecuador's Cuenca hope to carry their country's torch all the way to the final as their compatrios Liga de Quito, last year's champions, were ousted in the group stage. But Venezuela's Caracas stands in the way and will look to snatch a win in Ecuador. 

Venezuela has enjoyed moderate success on all fronts with their under-20 team qualifying that country to its first major international tournament, the World Cup in Egypt later this year and their senior national team still in the race to qualify to South Africa in 2010.  Caracas has been Venzuela's most successful team so far, topping several heavyweights in past Libertadores editions.

6:40PM ET
Argentina's Estudiantes de la Plata, three-time Libertadores champions, were left for dead earlier in the competition after several lackluster results but Juan Sebastian Veron & co. revived themselves in the last few matches of the group stages to qualify and now host Paraguay's Libertad.

The Paraguayans won their first four matches but eased back a bit when qualification was certain and lost their final two matches.

Both teams are healthy and should have their respective starting 11 in a very even match.

9PM ET
Brazil's Cruzeiro travel to Universidad de Chile without two key players in Argentine Juan Pablo Sorin, who's injured, and Fabricio, who's suspended. However, Cruzeiro did have former Brazil international Athirson plucked from second-division side Portuguesa for reinforcements.

U. de Chile could be without midfielder Marco Estrada and will be desperate to grab a first-leg win at home tonight since Cruzeiro has defeated and held all of its opponents goalless during this campaign.

MATCHES POSTPONED:
San Luis-Nacional of Uruguay
Chivas-Sao Paulo
Defensor Sporting-Boca Juniors

What do you think about these matches? Who do you see advancing? Is Libertadores vastly underrated? Why? Discuss below.