Sano played Saturday as the designated hitter despite the injury, which got worse as the game progressed. He finished Saturday's game against the Oakland Athletics 0-for-3 with three strikeouts but hit a sacrifice fly in the ninth inning that gave the Twins the lead before Oakland rallied to tie, later winning in extra innings.
Sano left the stadium Saturday on crutches.
The ball that Sano stepped on before Saturday's game was rolling in from the outfield. He was doing first base drills at the time of the mishap.
"We should have done a better job of clearing the field,'' Twins manager Paul Molitor told reporters, according to the Star Tribune.
Molitor told reporters that the Twins hope Sano is only sidelined for three to five days.
Sano has impressed in his first 13 games in the majors, batting .326 with two home runs and nine RBIs.