PHOENIX -- The Brewers placed first baseman Travis Ishikawa on the 15-day disabled list Sunday, one of several new names added to the team's growing list of injured players.

Ishikawa is dealing with a left rib-cage strain and will be replaced beginning Monday by Brooks Conrad, who was 0-for-21 in his first stint with the Brewers this season.

Manager Ron Roenicke revealed Ishikawa's ailment on Sunday morning after meeting with his coaches and then with assistant general manager Gord Ash. They discussed how to best manage the myriad of issues facing the Brewers, who have six players on the disabled list plus a handful dealing with bumps and bruises.

By the end of the day, the latter group included:

• Reliever Kameron Loe, who Roenicke revealed was not available this weekend in Arizona because of right elbow discomfort.

• Catcher George Kottaras, who experienced hamstring cramping while scoring a run in the sixth inning of Sunday's 4-3 loss to the D-backs and is considered day to day.

• Center fielder Carlos Gomez, who is still not running at 100 percent since returning from a hamstring strain.

• And third baseman Aramis Ramirez, who was forced to miss a second straight start Sunday with a bruised left elbow.

Ramirez was hurt on a ninth-inning hit by pitch on Friday night. The Brewers are hopeful he'll return Monday in Los Angeles.

"We're banged up," Roenicke said.

Ishikawa started feeling discomfort on his left side during the Brewers' May 16-17 visit to Houston, though he's not sure how he was hurt. He had played in five games since.

With Ishikawa out, the Brewers could use a combination of Corey Hart, the erstwhile right fielder, Conrad and young Taylor Green at first base. But as long as Ramirez remains sidelined, the Brewers also need Green at third.

Gomez's issue is less concerning. He spent two weeks on the DL this month and has been working back to full speed.

"He doesn't really feel it, but there's always that apprehensiveness of not going 100 percent," Roenicke said. "He doesn't want to go like 'Gomey' usually goes. It affects his game."

Fiers looks like Brewers' pick for rotation

PHOENIX -- When Wily Peralta started for Triple-A Nashville on Sunday, the Brewers' choice for their rotation vacancy became clear: Barring a last-minute change, it looks like right-hander Mike Fiers will pitch on Tuesday at Dodger Stadium.

The Brewers need a replacement starting that day for Marco Estrada, who went to the 15-day disabled list after straining his quadriceps last week in Milwaukee. The primary candidates were Peralta, Fiers or left-handed reliever Manny Parra, though manager Ron Roenicke has expressed a desire to preserve Parra's role in the bullpen.

On Sunday morning, Roenicke stopped short of officially naming Fiers his starter for Tuesday. If Fiers is the choice, he would be pitching on regular rest.

"We're going to need two starts for sure, we feel," Roenicke said. "We don't know how quickly Estrada is going to come; initially it was probably a little longer than just two starts, but he's coming along pretty good."

Fiers, who made two relief appearances for the Brewers in September, is 1-3 with a 4.42 ERA in 10 starts this season for Triple-A Nashville. The 26-year-old command specialist was a 22nd round Draft pick in 2009 and has a 2.80 ERA in four Minor League seasons, with 370 strikeouts vs. 91 walks in 346 2/3 innings.

Fiers would be the Brewers' seventh starting pitcher. In 2011, they used only six starters all year.

And general manager Doug Melvin remains on the lookout for more. The Milwaukee Journal Sentinel reported that the Brewers checked in on free agent Roy Oswalt but found his asking price too high for a half-season.

Brewers batting order in flux

PHOENIX -- Another day, another new Brewers lineup.

Milwaukee ranks near the bottom of the National League in 2012 lineup permutations, but has been charging up the list. Manager Ron Roenicke used a new order for the 11th straight game on Sunday, fielding the team's 32nd different starting lineup in 47 games.

With Travis Ishikawa bothered by a rib-cage issue, Corey Hart started at first base against a right-handed pitcher for the first time. And with third baseman Aramis Ramirez still out with a bruised elbow, catcher George Kottaras made his first career start in the cleanup spot.

"There's a whole bunch of stuff going on," Roenicke said. "I've never had so many days in a row where you're fighting with who to put out there in the lineup. It has been [taxing]. Last year was really easy. ... The thoughts were when somebody is a little banged up, 'OK, he needs a day.' Other than that, it was the same."

He joked: "In other words, last year was just a push-button club, wasn't it?"

Not exactly, but this year has certainly been more challenging. Roenicke far preferred the stability of 2011.

"No doubt about it," he said. "It's so nice coming in knowing those same guys are going to be there every day in that same order."

That's rare. Consider Sunday's opponent, the D-backs, who used their 44th different batting order on Sunday.

Last call

• Shortstop Cesar Izturis said his strained left hamstring was feeling much better on Sunday, two days after he was hurt running the bases at Chase Field and placed on the DL. Whether he needs more than the minimum 15 days on the DL depends on when he's strong enough to resume running, Izturis said.

• Outfielder Norichika Aoki is hitting his way closer to a spot in the Brewers' everyday lineup, but that would probably mean a permanent move for Hart to first base. Roenicke indicated that those discussions are still ongoing.

"It could happen, but we haven't made the decision that this is what we're doing with Corey, that he's our first baseman," Roenicke said.

After going 2-for-5 on Saturday night, Aoki was batting .390 (16-for-41) over his last 15 games. He is the first Japanese position player in Brewers history.