"It's a mild strain," Twins manager Ron Gardenhire said. "It's in his lower left side. He felt it on the throw. He wanted to go back out but I told him to throw in the cage. So he took a trainer in there but still felt it a little bit. So it's mild but it's a strain, so he's day to day."
Santana was removed for pinch-hitter Chris Parmelee in the bottom of the second. But Aaron Hicks was caught stealing while Parmelee was at bat to end the inning. Parmelee connected on a solo blast off Angels left-hander Michael Roth to lead off the third, tying the game at 3.
Hicks moved over from left field to center field to replace Santana defensively, while Parmelee remained in the game in left field.
Santana, 23, is hitting .320/.358/.475 with seven homers, 19 doubles, six triples and 15 stolen bases in 84 games this season. The natural shortstop has started 57 games in center and 21 at short.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.