A bone scan of Yonder Alonso's ailing lower back revealed a stress reaction.
Yonder Alonso felt continued tightness in his lower back while swinging a bat recently.
Yonder Alonso (back) played catch and took dry swings prior to Saturday's game.
Padres assistant general manager Josh Stein said Thursday that Yonder Alonso (back) will be sidelined for a "couple more days."
Yonder Alonso left Tuesday's game versus the Rangers with lower back tightness.
Yonder Alonso doubled and homered in four at-bats as the Padres took care of the Braves on Monday.
Yonder Alonso (head) is not in the Padres' lineup Sunday, but interim manager Pat Murphy said the first baseman is "fine."
Yonder Alonso had to leave Saturday's game versus the Rockies after being struck in the head with teammate Justin Upton's helmet.
Yonder Alonso hit his third homer of the year Friday against the Marlins.
Yonder Alonso is hitting leadoff for the first time in his career on Friday.
Yonder Alonso is starting at third base on Thursday.
Yonder Alonso will start at third base Saturday against the Dodgers.
Padres activated 1B Yonder Alonso from the 15-day disabled list.
Yonder Alonso (shoulder) is expected to be activated from the disabled list on Tuesday.