BUENOS AIRES, Argentina (AP) - Peruvian newcomers Bolognesi and San Martin will face two of South America's biggest clubs in their Copa Libertadores debuts on Wednesday.

Bolognesi takes on Brazilian side Flamengo at home in Tacna in Group 4 of South America's premier club championship, while San Martin welcomes Argentina's River Plate in Lima in two of the eight first-round matches played this week.

Bolognesi and San Martin have never even played in the preliminary rounds of Libertadores before, while Flamengo won the tournament in 1981 and River captured the crown in 1986 and 1996.

"We will be going up against one of the greats and the main thing is not to start out by losing," Bolognesi coach Juan Reynosa said. "The key will be sticking to our tactical strategy."

Bolognesi won Peru's Clausura title and San Martin took the country's Apertura crown, allowing the clubs to qualify directly for the Libertadores opening round.

But even if they are newcomers, rivals say the small Peruvian clubs will not be underestimated.

"They are going to play all out. They will be a complicated rival," said new River coach Diego Simeone.

San Martin coach Victor Rivera said his squad had spent days analyzing River's playing strategy and appeared unfazed by his opponent.

"They don't seem to me to be so fearsome," he said.

The tournament includes 32 teams in eight groups, with the top two teams in each group advancing to the next round in late April. The two-leg final will be held June 25 and July 2.

Play opens Tuesday as Caracas hosts Argentine club San Lorenzo and Deportivo Cuenca of Ecuador welcomes Estudiantes of Argentina in Group 2. The group's other teams, Danubio of Uruguay and Lanus of Argentina, play Thursday in Buenos Aires.

One preliminary match remains to be played as Audax Italiano of Chile hosts Chico of Colombia on Tuesday for the last spot in the group phase. Chico won the first of a two-leg series at home in Bogota.

Bolognesi's group also includes Cienciano of Peru and Nacional of Uruguay, who face each other Thursday in Cuzco, Peru. In San Martin's group, Universidad Catolica of Chile and America of Mexico play Feb. 20 in Mexico City.

Caracas and San Lorenzo are in Group 1 with Real Potosi of Bolivia and Cruzeiro of Brazil, who play Wednesday in Belo Horizonte.

Also Wednesday, Cucuta of Colombia will play at home against Brazilian club Santos in Group 6. Other Group 6 members Chivas of Mexico and San Jose of Bolivia meet Feb. 19 in Guadalajara.

Argentina's Boca Juniors, the defending champion, will make its debut Feb. 20 on the road against Maracaibo of Venezuela in Group 3, which also includes Atlas of Mexico and Colo Colo of Chile.