Juan Rivera, a Venezuelan-born outfielder, embarked on his Major League Baseball journey with the New York Yankees. Signed as an amateur free agent in 1996, Rivera spent several years honing his skills in the minor leagues before making his MLB debut with the Yankees in 2001. His time in New York was marked by limited opportunities, as he played in a crowded outfield that included stars like Bernie Williams and Paul O'Neill.

In 2003, Rivera was traded to the Montreal Expos, where he began to see more regular playing time. During his stint with the Expos, Rivera demonstrated his ability to contribute both offensively and defensively. His performance caught the attention of the Anaheim Angels, who acquired him in a trade before the 2005 season.

Rivera's tenure with the Angels proved to be the most stable and productive period of his career. He became a regular fixture in the Angels' lineup, known for his solid batting average and occasional power. In 2006, Rivera enjoyed one of his best seasons, hitting .310 with 23 home runs and 85 RBIs. His efforts helped the Angels remain competitive in the American League West.

Unfortunately, Rivera's momentum was halted by a broken leg suffered during winter ball in Venezuela, causing him to miss a significant portion of the 2007 season. Despite this setback, he returned to the Angels and continued to be a valuable player, though his role varied between starting and coming off the bench.

In 2011, Rivera was traded to the Toronto Blue Jays, where he played for part of the season before being dealt to the Los Angeles Dodgers. His time with the Dodgers was brief, but he managed to provide some veteran presence and depth to their roster.

Rivera's final MLB season came in 2012 with the Dodgers. Afterward, he continued to play professionally in various leagues, including stints in the Mexican League and the Venezuelan Winter League, before eventually retiring from professional baseball.