Fowler left St. Louis' 7-6 loss to the Pittsburgh Pirates in the eighth inning with a left foot injury. X-rays taken later showed a slight fracture, and Fowler was placed on the 10-day disabled list on Saturday.
General manager John Mozeliak said Friday night that Fowler told trainers he felt a pop in his foot while running the bases. He will be re-evaluated later this weekend, at which point the team will have a timetable for how long he'll be sidelined.
Fowler is hitting .180 with eight home runs and 31 RBIs this season.
"It sort of sums up our year in a lot of ways," Mozeliak said of the injury.
Second baseman Kolten Wong was activated from the 10-day DL in a corresponding move Saturday.
Wong had been out since July 22 with left knee inflammation. He is hitting .216 with seven homers and 24 RBIs in 91 games.
The Associated Press contributed to this report.