A standout player on the
UCLA baseball team and teammates with
Troy Glaus and Garret Atkins, Byrnes made his major league debut with the
Oakland Athletics in
2000. However, Byrnes didn't truly play a full season until
2004, when he slugged 20 home runs, drove in 73, and batted .283 for the season. Byrnes had a wacky season in
2005, playing for three different teams in the space of 111 games: the A's, the
Colorado Rockies, and the
Baltimore Orioles. In
2006, however, Byrnes settled down in
Arizona, and began gathering timely hits for the young and often struggling team. He set career highs in home runs and RBIs in 2006, and performed similarly in
2007