Boca Juniors, San Paulo favorites in Copa Lib

MONTERREY, Mexico: Boca Juniors and Sao Paulo are among the favorites as the Copa Libertadores begins its knock-out phase this week with 16 teams contending for the most prestigious prize in Latin American club football.

Brazil has five clubs in the final 16 with Argentina, Mexico and Uruguay each supplying two. Missing is defending champion Liga de Quito, and two high-profile Argentine clubs are also absent: River Plate and San Lorenzo.

The two Mexican clubs in the chase - San Luis and Chivas of Guadalajara - have had their first-leg matches delayed by a week as officials monitor the swine flu outbreak in the country.