Guerrero signed with the
New York Yankees as an amateur free agent in 1968. After four plus seasons in their farm system, he was sent to the
Boston Red Sox on June 30, 1972, as the
player to be named later in the deal that brought future
Cy Young Award winner
Sparky Lyle to the Yankees in exchange for
Danny Cater. Guerrero made the Red Sox out of
spring training 1973 and appeared in 66 games as a backup to starting shortstop
Luis Aparicio and second baseman
Doug Griffin. The Red Sox released Aparicio during spring training in March 1974, clearing the way for Guerrero to become the team's starting shortstop. He wound up sharing the position with rookie
Rick Burleson, however, with Burleson ultimately totaling more games and plate appearances than Guerrero while dividing his time between short, second base and third. In early April 1975, the Red Sox traded Guerrero to the
St. Louis Cardinals for a player to be named, with
pitcher Jim Willoughby eventually going to the Red Sox, on July 4. Guerrero split 1975 between the Cardinals and their triple A affiliate, the
Tulsa Oilers, batting .239 in 64 games at the major league level. He was assigned to Tulsa in 1976 when he was traded to the
California Angels for two minor leaguers. Guerrero signed as a free agent with the
San Francisco Giants after the 1977 season, only to be sent to
Oakland Athletics on April 7, 1978, to complete a trade in which the Athletics also acquired
Gary Thomasson,
Gary Alexander,
Dave Heaverlo,
John Henry Johnson,
Phil Huffman,
Alan Wirth and $300,000 for
Vida Blue just over three weeks earlier on March 15. He played three seasons in Oakland before his contract was purchased by the
Seattle Mariners. Guerrero retired following his release from the Mariners in spring training 1981. Although Guerrero played in 697
games over 8 seasons and collected over 500 career
hits, he finished with exactly 0 career
wins above replacement (WAR). This suggests that, statistically, his overall contributions to his teams were equivalent to those of a readily available
replacement-level player, typically someone from the
minor leagues, rather than elevating the team's performance above that baseline. ==Personal life and death==