Hafner's last at-bat ended with a home run -- the 200th of his career -- against the Tigers on Sunday. Since then, Hafner's lower back has flared to the point where the Indians were forced to place him on the 15-day disabled list on Thursday.
Head athletic trainer Lonnie Soloff offered more detail on Friday, explaining that Hafner has a bulging disk in his lumbar spine. Hafner is currently taking anti-inflammatories and he received an epidural injection on Friday to help the swelling.
"Any any of us, it could flare up at any given time," Soloff said. "The fact that he's a power hitter and spends a lot of his time in flection and rotation is certainly a cause of it as well. Our hope is that with the medication, the epidural and the treatment, he's going to feel better."
At this point, the club did not believe surgery was necessary, Soloff said.
"Anything is possible," Soloff said, "but I think that we're optimistic that it'll be a conservative case for us."
Soloff noted that Hafner's back injury flared up after the team's flight from Minnesota to Kansas City on July 29. The DH played against the Royals on July 31, but he was pulled for a pinch-hitter in the eighth inning. After going on baseball's paternity list for three days, Hafner returned to the lineup for Sunday's game in Detroit.
The issue never subsided.
It's the second stint on the DL for Hafner this season. He was sidelined for nearly six weeks after undergoing right knee surgery on May 31. In 60 games this season, he is batting .239 with 11 home runs and 32 RBIs.
Hafner had hit .320 (8-for-25) with three home runs in his seven most recent games.
As of right now, there is no known timetable for his return.
"It will depend solely on his responses to the medication, the injection and the treatment," Soloff said.