Taveras crashed his 2014 Chevrolet Camaro on a highway about 215 miles north of Santo Domingo, according to the AP.
Considered one of the league's top prospects, Taveras had just completed his first year in the major leagues, finishing with a .239 batting average, 22 RBIs and three homeruns in 80 games.
Born in the Dominican Republic, Taveras signed with St. Louis in 2008 as an international free agent.
"I simply can't believe it," Cardinals general manager John Mozeliak said in a statement, according to the AP. "I first met Oscar when he was 16 years old and will forever remember him as a wonderful young man who was a gifted athlete with an infectious love for life who lived every day to the fullest."
MLB commissioner Bud Selig complimented Taveras' performance in the NLCS a couple of weeks ago against the San Francisco Giants, who are currently playing in the World Series. "All of us throughout Major League Baseball are in mourning this evening," Selig said in a statement. "Oscar, a young member of the baseball family, was full of promise and at the dawn of a wonderful career in our game, evident in his game-tying home run against the Giants exactly two weeks ago."
Several players learned of Taveras' death during Game 5 of the World SeriesSunday night.
Perez dedicated his two-run double in the eighth inning to Taveras. "He's a really close friend of mine," Perez told the AP. "We were really close. It's a huge loss for all his family, his teammates and the people that care about him."