Morris has had four MRIs since before the 2014 season, and until now, has been able to manage the discomfort.
"We found out with this MRI that I got a little more than just those two discs that are herniated," Morris said. "The winter of '14 is when I got my first MRI, and I realized that it was messed up."
Morris believes he initially injured his back while working out in the offseason prior to the 2014 season.
The right-hander dealt with back issues in Spring Training. Once the season started, he never felt quite right.
In 24 appearances, Morris posted a 3.06 ERA with 13 strikeouts and 10 walks.
"I've been pitching with it the past two years," Morris said. "Last year, I was capable of managing the symptoms. This year, I managed it in Spring Training, but it quickly wore off."
If surgery is required, Morris said he would likely miss the rest of the season, but he could return in 2017.
• Christian Yelich, who struck out looking in a pinch-hit at-bat in the sixth inning of Saturday's 7-2 loss to the Braves, could be ready to start on Sunday in the series finale in Atlanta. He has been sidelined with back spasms.
"I'm hoping," manager Don Mattingly said. "I think he's encouraged. It sounded like he had a little pep in his step today. That usually tells you a guy is doing better."
• Giancarlo Stanton, out with a sore right side, is increasing the intensity of his hitting program as he moves closer to returning to the lineup. The three-time All-Star right fielder has not started since Monday. It's unlikely he will play before the club returns to Marlins Park to face the Pirates on Monday.
• Lefty reliever Mike Dunn, on the DL with a left forearm strain, threw a scoreless inning in a rehab assignment on Friday for Class A Advanced Jupiter. Dunn could come off the disabled list at some point during the four-game series with the Pirates.