José Guillén's journey through Major League Baseball (MLB) was marked by a series of team changes and a reputation for a powerful arm and bat. Born on May 17, 1976, in San Cristóbal, Dominican Republic, Guillén began his professional career when he was signed by the Pittsburgh Pirates as an amateur free agent in 1992. He made his MLB debut with the Pirates on April 1, 1997, showcasing his potential as a right fielder.

Guillén's early years with the Pirates were a learning curve, as he adjusted to the demands of the major leagues. His tenure with Pittsburgh lasted until 1999, when he was traded to the Tampa Bay Devil Rays. His time with the Devil Rays was brief, and in 2001, he found himself with the Arizona Diamondbacks, although his stint there was short-lived as well.

The following years saw Guillén moving frequently between teams. In 2002, he joined the Cincinnati Reds, where he began to demonstrate his offensive capabilities more consistently. His performance caught the attention of the Oakland Athletics, who acquired him in 2003. That same year, he was traded to the Anaheim Angels, where he played a crucial role in their lineup, hitting .337 with 23 home runs in just 99 games.

Guillén's career continued to be characterized by frequent team changes. In 2004, he signed with the Washington Nationals, where he played for two seasons. His time with the Nationals was marked by solid offensive production, including a career-high 104 RBIs in 2005. However, his tenure with the team ended on a sour note due to disciplinary issues, leading to his release.

In 2006, Guillén joined the Seattle Mariners, where he played for one season before signing with the Kansas City Royals in 2008. His time with the Royals was notable for his power-hitting, as he hit 20 home runs in his first season with the team. However, injuries and controversies, including a suspension for performance-enhancing drug allegations, marred his later years with Kansas City.

Guillén's final MLB season came in 2010, during which he played for both the Royals and the San Francisco Giants. Although he was part of the Giants' roster during their World Series-winning season, he was left off the postseason roster due to ongoing investigations into his alleged involvement with performance-enhancing drugs.

Throughout his career, José Guillén was known for his strong throwing arm and ability to hit for power.