Sano fouled a ball off his shin Friday night, the same night he hit two home runs in a 10-3 rout of the Arizona Diamondbacks.
Sano had to leave Saturday's game in the seventh inning because of soreness in the shin.
He is hitting .267 with 28 home runs and 77 RBIs but also leads the major leagues with 170 strikeouts.
First baseman Kennys Vargas was recalled from Triple-A Rochester for the fifth time this season to fill Sano's spot. The Twins also designated left-hander Nik Turley as their 26th player for the doubleheader against in Chicago and summoned right-hander Tim Melville from Rochester so he could start the first game against the White Sox.