Copa Libertadores semifinals begin with River-Boca rematch

The Copa Libertadores semifinals start Tuesday with a rematch of last year's troubled final as defending champion River Plate faces Argentine rival Boca Juniors.

The 2018 final was moved to Spain for the first time in its history because of fan violence prior to the second leg.

This year's final is on Nov. 23 in Santiago.

Brazil's Gremio and Flamengo meet in the other semifinal of South America's most prestigious club tournament, with the first leg on Wednesday.

River and Boca meet almost one year after River won in Madrid.

"This match is not the decider. We hope to win and reach a good result, but if we don't get it we will have another chance, we are dangerous visitors," said River coach Marcelo Gallardo.

After the final in Spain, Boca managed to regroup under a new coach, Gustavo Alfaro, and his team leads the league in Argentina.

While Alfaro has coached Boca for 40 matches, with 23 wins, 14 draws and only three defeats, he knows what really counts.

"Obviously my work will be judged as good or bad depending on advancing against River or not," he said.

River has kept most of its title-winning team from last year, and Boca has changed much of it.

Boca's Carlos Tevez is expected to start on the bench.

In the other semifinal, 2017 champions Gremio are relying on striker Everton to advance against Brazilian championship leaders Flamengo.

"Flamengo is the favorite for sure," said Gremio coach Renato Portaluppi, adding his opponent plays an effective attacking style of soccer.

"But I am very calm before this clash, I trust my group a lot. We have a lot of Libertadores experience," Portaluppi said.

Gremio captain and defender Pedro Geromel is expected to sit the match out due to injury.

Flamengo is untroubled by injuries as the Rio de Janeiro giant chases its second title and first since 1981.

Gremio wants its fourth South American crown, while Boca seeks its seventh and River goes for its fifth.