The Toronto Blue Jays outfielder will begin his rehab stint as a designated hitter for the triple-A Buffalo Bisons on Thursday in Rochester, N.Y., against the Red Wings, Blue Jays manager John Schneider confirmed.
Santander experienced back tightness early this week, delaying the start of his rehab stint for a couple of days.
The plan is for Santander to DH the first few games before getting some reps in both right and left field. The Blue Jays will be trying to determine what role, if any, Santander can play with the major-league club in the last few weeks of the regular season and playoffs.
Santander, a switch-hitter, travelled with the Blue Jays to New York last weekend to get more right-handed reps with the bat before games against the Yankees.
The outfielder has been out since May 29 due to a left shoulder subluxation he sustained crashing into a wall in a game against the Los Angeles Angels. He struggled during the first two months of the season, hitting for a .179 average and .577 OPS with six home runs.
The 30-year-old signed a five-year, $92.5-million contract with the Blue Jays in the off-season that includes a third-year opt-out, sixth-year team option and deferred money.
Santander hit a career-best 44 home runs with the Baltimore Orioles last season and could offer both power and versatility as a switch-hitter to the Blue Jays lineup.