Buck could earn a $625,000 salary if he makes the Tribe's Major League roster.
Buck -- an Opening Day outfielder for the A's each of the past three seasons -- was slowed by various injuries during that time. After Buck appeared in only 14 Major League games for Oakland in 2010, the A's decided against tendering the outfielder a contract for the upcoming season.
Buck's best season came as a rookie in 2007, when he hit .288 with seven home runs, 22 doubles and 34 RBIs in 82 games for the A's. Over parts of four seasons with Oakland, he hit at a .250 clip with a .330 on-base percentage. Buck also made no errors over 180 games in the outfield.