Capps last pitched on May 25, and the right-hander has been on the DL since May 27 with an elbow sprain. He's currently working out at the team's complex in Jupiter, Fla., where he is throwing.
The way the schedule is worked out, Capps could be facing hitters soon and be ready to be reinstated around Sept. 1.
"I think that's kind of when we anticipate he will be ready to go, either right before or right around Sept. 1," Miami manager Mike Redmond said.
Capps received a scare in late May, and he was examined by noted surgeon Dr. James Andrews, who indicated the reliever did not need surgery.
In nine appearances with the Marlins, the hard-throwing right-hander has struck out 15 and walked three in 12 innings.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter