The goalie did not practice with the Wild after he made 23 saves in a 2-1 loss at the Nashville Predators on Tuesday. By being placed on IR, Fleury can miss no fewer than seven days.
"It's hard to say too much," Wild coach Dean Evason said. "It's just an upper-body injury that we hope will be shorter than longer. We'll continue to evaluate. (He's) getting treatment and getting it looked after, so hopefully we'll have it sooner rather than later.
"I don't know [what happened]. There's several situations, a lot of contact in that game (in Nashville) both ways. Both goalies got bumped a lot. I'm not going to get into details. We're not 100 percent on the exact time of that."
Zane McIntyre was recalled from Iowa of the American Hockey League to replace Fleury, who is 6-4-1 with a 2.80 goals-against average, .906 save percentage and one shutout in 12 starts this season.
McIntyre is 4-3-0 with a 3.08 GAA and .903 save percentage in seven AHL games this season. He went 0-4-1 with a 3.97 GAA and an .858 save percentage in eight NHL games (three starts) for the Boston Bruins in 2016-17.
Fleury was selected by the Pittsburgh Penguins with the No. 1 pick in the 2003 NHL Draft. The 37-year-old is 526-303-86 with two ties and 72 shutouts in 951 games with the Penguins, Vegas Golden Knights, Chicago Blackhawks and Wild. He ranks third on the NHL all-time wins list, sixth in games played and 12th in shutouts.
Goalie Filip Gustavsson started and made 26 saves for the Wild in a 6-4 loss to the Penguins on Thursday.
NHL.com independent correspondent Jessi Pierce contributed to this report
