Morris went on the disabled list last Thursday with a lumbar disc herniation.
"Best-case scenario is I pitch in September, which, obviously, is the ultimate goal," Morris said. "But at the same time, we've got to make sure everything is 100 percent before we take that step."
Morris opened the season as the club's primary eighth-inning setup option, but he ended up mostly used in the seventh inning or earlier.
In 24 games, he logged 17 2/3 innings, posting a 3.06 ERA with 13 strikeouts, 10 walks and a WHIP of 1.42.
Morris noted he has been dealing with the back issue off and on since 2014. The issue resurfaced in Spring Training, and he's been able to manage the discomfort until early last week.
The right-hander broke in with the Pirates in 2012, and he was traded to the Marlins in '14. In that season, he combined to go 8-1 with a 1.82 ERA in 64 1/3 innings.
"The first few weeks is supposed to be pretty light, no activity, to let everything heal, specifically the incision," Morris said. "Then we'll go from there."
Joe Frisaro has covered the Marlins for MLB.com since 2002. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.