Sizing up the Libertadores final 16

Who will stop the boys from Brazil? With all five representatives gaining entry into the knockout phase of the 50th edition of the Copa Libertadores, there's a great chance that a club from Brazil will emerge as South American champions come finals time in July.

Brazilian teams have demonstrated that they're a cut above the rest in terms of overall quality this year, and their domination is evidenced by the fact that all five of its teams (except, perhaps, for Palmeiras) advanced to the knockout phase without complications (the round of 16 gets underway Tuesday night).

From the five, the most impressive has been Grêmio. Not only did the two-time Libertadores champions go undefeated through the group stage, but they did so with an attractive style of free-flowing soccer. As is traditionally the case, former winners São Paulo, Cruzeiro and Palmeiras also have been very strong, while outsider Sport Recife has used its underdog tag to surprise its opposition.

From the remaining participants, a number of teams also have proved their worth. The main clubs expected to break the Brazilian juggernaut are Boca Juniors, Nacional and perhaps Libertad. Mexican clubs Chivas de Guadalajara and San Luis may have just sneaked into the knockout phase, but both will be motivated to edge Mexico closer toward a first title triumph.

Here's a breakdown of all eight matchups, with picks for the clubs to advance to the quarterfinals.

Cleiton Xavier's spectacular last-gasp strike sent Palmeiras into the last 16 at the expense of Colo-Colo and set up another showdown with fellow Brazilians Sport Recife. Both teams are familiar with one another after meeting in the group stage, with Palmeiras grabbing four of the six points in play. Expect a thrilling series between two teams that emphasize the attack and tend to exhibit the traditional Brazilian flair. If there's one player who could decide the outcome, it's Barcelona target Keirrison, the Palmeiras striker who leads the tournament with six goals.

The pick: Palmeiras

Both Colo-Colo and Everton were eliminated dramatically last week, leaving Universidad de Chile as Chile's sole representative in the final 16. La U has never won South America's ultimate prize, but will rate its chances rather highly this year after spending big money in reinforcing its squad for the tournament. Unfortunately, the Chileans will be up against Cruzeiro, which also boasts an incredibly talented squad. The Belo Horizonte giants may be one of the strongest teams in the competition, but also revealed their weaknesses in a 4-0 thumping at the hands of Estudiantes de La Plata in the group stage. Which is Cruzeiro's real face?

The pick: Cruzeiro

Libertad kicked off the tournament with four consecutive victories, but the Paraguayans seemed to take their foot off the pedal once qualification was sealed and ended up losing their final two games. Although Libertad still won its group rather comfortably, it will have to regain its form to eliminate a confident Estudiantes. In contrast to Libertad, the three-time Copa champions have risen from the dead in recent weeks, and Juan Sebastián Verón will be eager to help the side end a 39-year wait for another international title. This is likely to be one of the most evenly balanced matchups of the round of 16.

The pick: Libertad

Boca is the overwhelming favorite to win a record seventh title, but the fact that it languishes toward the bottom of the Argentine Clausura Championship means it has to improve a great deal to get the better of the Uruguayans. Defensor progressed to the last 16 with a dramatic 4-3 victory over Independiente Medellín in Montevideo, and such a performance will likely motivate it ahead of one of the biggest games in its history.

The first leg of the tie will be postponed until next week because a concert will be staged at the Centenario stadium on the same day as the match was scheduled. The news comes as a relief for Carlos Ischia and the Boca camp, as Juan Román Riquelme should be recovered from a lengthy injury layoff by then. Without Riquelme, Boca has managed only one victory in seven matches. But with or without the playmaker, Boca has vast experience in these kinds of situations, and its strength and determination should steer los Xeneizes closer to seventh heaven.

The pick: Boca

This is easily the least attractive matchup of the round of 16. Both teams are relative minnows of the continent with little tradition in the competition. Neither of the two is expected to go much further but, regardless, both will be hoping to prove the skeptics wrong. Deportivo Cuenca, who has found a star in Brazilian striker Rodrigo Teixeira, has never reached this stage before and will be highly motivated after beating Boca in a tight contest last month. But does Cuenca have what it takes to be last year's Liga de Quito?

The pick: Caracas

Grêmio enters the knockout phase as the best-ranked team with five wins and a draw from its six group matches. Such an impressive start is much of the reason why it's expected to breeze past bottom-ranked Universidad San Martín of Peru. The Brazilians demonstrated the necessary depth to progress to the decisive stages of the tournament, but even if they're too hot to handle for the Peruvian champions, they can't let it go to their heads. This is by far the most one-sided matchup of this round, and anything but a Grêmio victory would be considered a major shock.

The pick: Grêmio

Nacional cruised into the knockout phase in style, joining Grêmio as the only unbeaten teams in the group stage. Nacional leads the competition in goals with 12, and will be expected to overcome a San Luis side that only squeezed into the last 16.

The Mexican outsiders -- who count U.S. national-teamer Michael Orozco among their ranks -- know they come into the matchup as the clear underdog. But their heroic 2-0 victory over Libertad in Paraguay last week indicates they can pick up important results when they set their mind to it. Perhaps the biggest disadvantage for San Luis is that it will be forced to play its home leg in neutral territory as a precaution for the swine flu in Mexico. Nacional will be hoping to make the most of this before deciding the series at the intimidating Parque Central stadium in Montevideo.

The pick: Nacional

When it comes to the Libertadores, few teams can match the achievements of São Paulo. With three straight Brazilian league titles, São Paulo has proved to be one of the strongest teams on the continent, and its display in the group stage of the Copa suggests it certainly should be a title contender. With the likes of stars Hernanes, Borges and Miranda, São Paulo can make a worthwhile claim.

The Tricolor Paulista will recall eliminating Chivas from the semifinal stage of the competition in '06 after a massive 4-0 aggregate victory. But the Mexicans will be confident of avenging that defeat even if they also will be forced to play away from home, and without defender Héctor Reynoso, who was banned for the remainder of the tournament after his "swine-flu" cough at an Everton player last month.

The pick: São Paulo