CLEVELAND -- Travis Hafner's unfortunate cycle of health woes has come back around to bite the Indians once again.

Cleveland placed the veteran designated hitter on the 15-day disabled list with lower back inflammation on Thursday and recalled infielder Jason Donald from Triple-A Columbus to assume his spot on the roster.

"There's not a specific timeframe at this point," said general manager Chris Antonetti, when asked how much time Hafner might miss.

Manager Manny Acta added that head athletic trainer Lonnie Soloff would discuss Hafner's injury in more detail on Friday.

Hafner's placement on the DL is retroactive to Monday. He last played Sunday, when he hit a home run and tallied three RBIs in Cleveland's 10-8 loss to Detroit. He sat out all three of the Indians' contests against the Twins this past week and had an MRI on his lower back on Wednesday.

The 35-year-old's back first flared up during a July 31 game against Kansas City. Hafner went on paternity leave on Aug. 1, when he and his wife welcomed the birth of their son, Trip. He returned to the ballclub on Saturday, but he sat out that night's tilt with the Tigers because of back stiffness.

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.

Donald, who was on the club's Opening Day roster, has hit .188 (9-for-48) in 18 games for Cleveland. The utility player batted .277 with six homers and 31 RBIs in 65 contests for the Clippers.

"Donald is going to get some playing time at third base," Acta said. "He could also move over to second and occasionally in the outfield, if we need him. Right now, with [Jose] Lopez not being here, he'll probably get most of his at-bats playing third."

Pitchers sad to see club part ways with Radinsky

CLEVELAND -- There is a sinking feeling that sets in for players when they see their team part ways with a well-liked coach. It is part of the business of baseball, but that fact does not always ease the sting.

On Thursday, Indians pitchers were coming to terms with the realization that their collective struggles led to the dismissal of pitching coach Scott Radinsky. That was tough news to swallow for the men around Cleveland's clubhouse.

"It wasn't Rad's fault, the problems we were having this year as a staff," starter Josh Tomlin said. "The people that need to be held accountable are the guys that are in this room, not the guys that are sitting in the dugout saying who pitches and when."

The Indians named Ruben Niebla, who has been in the organization for the past 12 seasons, the team's interim pitching coach, and will reassess the staff again at the end of the year. Niebla most recently served as pitching coach for Triple-A Columbus, and it is that experience that played a role in his promotion.

"At least three of our starters in our rotation pitched down there in Columbus for Ruben," said manager Manny Acta, referring to Zach McAllister, Corey Kluber and Chris Seddon. "We felt it was appropriate to give him an opportunity to come here and help us develop these guys."

The personnel change was especially hard on the Tribe's relievers.

Radinsky worked as Cleveland's bullpen coach for two seasons before replacing Tim Belcher as pitching coach this year. Under Radinsky's watch, the Indians' relief corps -- the late-inning arms, in particular -- developed into one of the better groups in the game.

"Without him, I don't know where I'd be," said reliever Joe Smith. "I know I wouldn't be here. He gave me the confidence to change my delivery back to what it was, and that's when I started to actually have some success consistently in the big leagues. It stinks that, because we've done so poorly, he takes the brunt of it. It's all on us."

Closer Chris Perez said Radinsky's impact went beyond the mound.

"He's helped me become a man. He's helped me become a father," Perez said. "I owe a lot of what I've become to him. ... I don't think it's all Rad's fault [that the staff has underperformed]. Most of it isn't his fault. It stinks. At the end of the day, it comes down to the pitchers.

"If we're leading the league in ERA right now and our starters are going out there and putting up six or seven solid innings every night, Rad's still here. It's an unfortunate circumstance to be a part of."

Damon's tenure with Tribe officially over

CLEVELAND -- The Indians had hoped that signing outfielder Johnny Damon would inject some life to their lineup. The deal did not pan out as expected and the club has now officially moved on from the experiment.

On Thursday, the Indians released Damon, along with reliever Jeremy Accardo, after designating both players for assignment last week. Cleveland is still working through its decision on veteran sinkerballer Derek Lowe.

Cleveland will likely release Lowe on Friday, if the club is unable to find a team willing to work out a trade. The Indians designated the 39-year-old for assignment on Aug. 2 after the right-hander went 8-10 with a 5.52 ERA in 21 starts.

Barring a trade, the Indians are on the hook for $5 million of the $15 million Lowe is scheduled to earn this season. The Braves, who traded Lowe to Cleveland in the offseason, are paying $10 million of the pitcher's salary.

Damon, 38, signed a one-year contract worth $1.25 million with the Indians in April and hit .222 (46-for-207) with four home runs and 19 RBIs in 64 games with the team. Accardo posted a 4.58 ERA in 26 relief appearances after signing a Minor League deal with the Tribe in the offseason.

Smoke signals

• Second baseman Jason Kipnis was scratched from Thursday's lineup due to neck stiffness shortly before the game against the Red Sox. Donald replaced Kipnis in the lineup as Cleveland's leadoff hitter and second baseman.

• Entering Thursday, Indians catcher Carlos Santana had collected 21 RBIs in 21 games, dating back to July 18. That was the second-highest RBI total in the Majors, trailing only Chris Johnson (22 for the D-backs/Astros).

• Pitcher Roberto Hernandez is scheduled to make a Minor League rehab appearance for Triple-A Columbus on Friday. Hernandez, whose three-week suspension ends Saturday, will likely be activated to join Cleveland's rotation next week.

• Due to their recent rotation problems, the Indians are currently carrying eight relievers. When Cleveland opts to return to its typical seven-man bullpen, either Matt LaPorta or Russ Canzler will likely be promoted from Triple-A Columbus.

Quote to note

"I don't think he's done coaching by a long shot. He's a talented pitching coach. And the way I know Rad, he's going to do everything can at his next stop to prove that he's that good. That's just how he is."
-- Closer Chris Perez, on former pitching coach Scott Radinsky