"Brad has a right ankle sprain," manager Mike Redmond said. "I guess he tweaked it on a pitch."
Hand's injury came at a time in which the 24-year-old had been struggling.
In 16 appearances, the lefty was 0-1 with a 6.38 ERA (17 earned runs in 24 innings). He has a live arm and boasts a mid-90s fastball. In 24 innings, he has 20 strikeouts and 16 walks.
In his past 10 2/3 innings, he has given up nine earned runs in 10 2/3 innings.
Hand, who is out of options, gave up two runs in two innings, including a home run to Khris Davis, on Friday in Miami's 9-5 loss to the Brewers.
"I feel like a broken record sometimes talking about our pitching and guys pounding the strike zone," Redmond said. "There really is some opportunity for some guys to solidify roles. We all talk about roles. Everybody wants a role. There are opportunities out there for guys to solidify their spots in that bullpen to get consistent reps."
Jennings falls into that category. He has also had his ups and downs at the big league and Triple-A levels.
With the Marlins, Jennings is 0-1 with a 1.59 ERA in 11 1/3 innings, including 14 hits allowed. Opponents are batting .304 against him, and he has struck out nine and walked four.
At Triple-A New Orleans, Jennings posted a 4.50 ERA in five outings. Jennings, who made the Opening Day roster, also has six strikeouts and six walks in six innings in Triple-A.
Miami's bullpen ERA entering Saturday was 3.96, which ranked 20th in the Majors.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter