Major League Baseball says Bieber will debut the music video for his song "Never Say Never" on Saturday during Game 3's pre-show on Fox.
The best-of-seven series is between the Texas Rangers and the San Francisco Giants. The Giants won the first two games of the series in San Francisco.
Game 3 will take place in Arlington, Texas. Former "American Idol" champion Kelly Clarkson will sing the national anthem in her home state.
The 16-year-old Bieber wears gear from both teams in the "Never Say Never" clip, which was shot at Angels Stadium in Anaheim, Calif.