SAN DIEGO -- The Brewers decided to place ace right-hander Ben Sheets on the disabled list on Wednesday, another blow to a starting rotation that has suffered two major losses in one week.

Sheets is suffering from right shoulder tendinitis and will join right-hander Tomo Ohka (shoulder) on the 15-day DL, retroactive to May 3. The team may wait to make a formal move until later in the week, but barring an unforeseen setback, Triple-A Nashville left-hander Dana Eveland will get the call to start on Saturday against the Mets at Miller Park.

"We just can't keep patching things up and going around Ben at this point," general manager Doug Melvin said. "We need to try to get the pitching in order, get a rotation back in order."

Sheets, who was tagged for seven runs by the Astros in his last start May 2, was scratched from his scheduled start on Sunday at Dodger Stadium and was originally penciled in to start on Thursday against the Padres. He was then was bumped to Saturday, but a decision to place Sheets on the DL was made after a throwing session on Tuesday was cut short.

"It's getting better. It's progressing, but it's just not where we want it to be," Brewers head athletic trainer Roger Caplinger said. "We want to let him go out there and be effective throwing."

Sheets played catch for several minutes, then conferred with Caplinger and a decision was made to stop.

"It didn't feel too good," said Sheets, who has now suffered two significant setbacks returning from the torn upper back muscle he suffered last August. "I didn't think it would be totally smooth sailing, but I didn't expect this. If I threw right now, I think it would be unfair to everyone else when we can have another guy up here who's completely healthy."

Sheets will be eligible to return as early as May 18, though the Brewers will not know anything about a timetable until Sheets sees the doctors at Miller Park later this week.

"That's the big mystery right now," Melvin said.

Sheets went 1-3 with a 6.64 ERA in four starts after beginning the year on the DL with a right shoulder strain. The current injury -- which Sheets said he first felt during the team's April 28-30 series against the Cubs -- is separate from that one, but Caplinger said they are likely related.

"Some people might think, 'Oh, man. Here we go. This is what we were waiting on,' " Sheets said. "But I want to be out there. I want to throw. Stuff just happens. It doesn't mean I can't be good this year and years to come."

More shuffling: Even before Sheets was lost, Brewers manager Ned Yost shuffled his rotation again.

Ben Hendrickson will now start Thursday's series finale at PETCO Park, Dave Bush will pitch the series opener against the Mets at Miller Park on Friday and Eveland is the most likely choice to start Saturday on three days' rest.

Eveland threw 70 pitches Tuesday night in Tucson, Ariz., and will slide into a regular spot in the Brewers rotation. He surrendered two runs, both unearned, in five innings of work for Nashville and has an 0.75 ERA after six starts.

Hendrickson will essentially serve as the No. 5 starter, and is only penciled in for three starts this month.

The Brewers were 16-16 entering play on Tuesday, and Yost admitted that the team might have to go into damage control.

"There is a danger that you can get unsettled to the point where it can put you in a bind," Yost said. "You have to hold your head above water until you can get it figured out."

Fielder sits: After re-aggravating his groin in Sunday's loss to the Dodgers, Prince Fielder sat out Tuesday's game and was replaced at first base by Jeff Cirillo.

Fielder received treatment for tightness in his right groin on the off-day Monday and was available for pinch-hit duties in the series opener against the Padres, Yost said. Fielder is expected back in the starting lineup on Wednesday.

"I'm going to play [on Wednesday]," Fielder confirmed. "It feels fine today. On the off-day, I went and rode the [stationary] bike and stretched it. It's fine, just a little tight."

Yost said Fielder originally tweaked his groin in the eighth inning on Thursday at Miller Park, but he started all three weekend games at Dodger Stadium and went 4-for-11. After grounding out in the top of the fourth inning, Fielder left the game.

The reigning National League Rookie of the Month, Fielder is batting .333 with five home runs and 18 RBIs. He turned 22 on Tuesday.

Last call: Right-hander Rick Helling (elbow), another major loss for the pitching staff, could throw his first mound session sometime this week but will not be back until at least early June, Yost said. ... Geoff Jenkins was back in the lineup on Tuesday, and Yost said he had no intention of moving the veteran out of the No. 3 hole. Jenkins entered play hitting .280 with five homers and 15 RBIs but was in an 0-for-9 skid. ... Carlos Lee set a club record for home runs in April, and was well on his way to his own May mark. Lee hit nine home runs last May to tie the mark set in 1974 by John Briggs, and already has four home runs in seven games this month. ... Wisconsin native Vinny Rottino got off to a slow start at Nashville but entered Tuesday's game with 11 hits in his last 24 at-bats.

On deck: Lefty Chris Capuano will try to make it 8-for-8 quality starts when he faces Chan Ho Park and the Padres at PETCO Park on Wednesday night at 9:05 p.m. CT. Capuano surrendered a season-high 10 hits to the Dodgers in his most recent start, but he has worked at least six innings and surrendered three or fewer runs in all seven of his starts this season.