Flowers sustained the injury on a swing in his first at-bat of the season in Atlanta's 8-5 win over Philadelphia on Thursday. He could not complete the at-bat and headed straight to the clubhouse.
Manager Brian Snitker said Friday that Flowers felt a pop. Snitker said the strain was diagnosed as being of midlevel severity.
"It's safe to say it's going to take a while," Snitker said, adding he expects Flowers will need "a couple weeks without doing anything" before taking the next step on his rehab.
Snitker said it was "a bummer, one of those freak things" for Flowers to get hurt on his first at-bat.
Snitker said Kurt Suzuki, who had been expected to split time with Flowers at catcher, will receive "the bulk" of the starts while Flowers is on the DL. Chris Stewart, already on the roster as the Braves opened the season with three catchers, will play behind Suzuki.
"I'm glad we kept him," said Snitker of Stewart. "This is what he does. His role is to be a backup."
The Braves selected the contract of right-hander Miguel Socolovich from Triple-A Gwinnett. To make room on the 40-man roster, left-hander Jacob Lindgren (left elbow surgery) was placed on the 60-day disabled list.