Vallejo underwent surgery in early February to repair severed tendons in the fourth and fifth fingers of his right hand and is expected to miss most of the 2010 season.
The 23-year-old native of the Dominican Republic, who's mostly a second baseman, was acquired from the Rangers in August 2009 as one of the players to be named later in the Ivan Rodriguez trade. Vallejo hit .250 with two homers, 38 RBIs and 10 stolen bases in Double-A and Triple-A last season.
Alden Gonzalez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.