But, "you can't rule anything out at this point," Ash added. "There's no benefit to that."
Sheets left his Tuesday start in Houston before he threw a pitch in the second inning and complained of "cramping" in his hamstring. When he still felt sore on Wednesday morning, the team sent him back to Milwaukee. Sheets underwent an MRI scan Thursday morning that was reviewed by head team physician William Raasch. The test confirmed a strain to the upper part of the muscle.
"He does have a hamstring strain. It is not significant," Ash said. "At this point, it is probably a day-to-day proposition as far as Sunday goes."
Sheets was expected back in Atlanta on Thursday night.
Should Sheets miss his turn in the rotation, right-hander Claudio Vargas likely would start. Vargas, a starter for much of this season who lost his spot when he suffered a back injury in late August, pitched four effective innings in relief of Sheets on Tuesday.
"It's still 50-50," Brewers manager Ned Yost said. "[Sheets] is still in the mix."
Sheets has battled myriad of injuries again this season. He left an April start after tweaking a groin muscle, then he had a start in May pushed back by a blister. Sheets then spent about six weeks on the disabled list in July and August with torn tissue in his right middle finger. His return from that injury was delayed by another bout of blisters.
There is one year remaining on the four-year, $38.5 million contract Sheets signed in April 2005. That contract guaranteed an $11 million base salary for 2008, and a limited no-trade clause kicks in that limits the Brewers to eight teams should they pursue a deal.
On Cordero: Yost said earlier this month that he would manage every day like it was the last day of the season, but that does not mean he would consider using closer Francisco Cordero in situations like Wednesday night, when the Brewers were tied on the road and headed for extra innings.
"I didn't say I was going to be stupid," Yost said. "I said I was going to pull out all the stops. If we would have had the lead in the eighth inning, I would have had CoCo in there. But we didn't.
Most Major League managers adhere to that rule. In a tie game on the road, a pitcher has to work two innings for every one inning his team gets to bat. Closers usually are held back for situations in which they can work with the lead.
"So if you put your stopper in the game, you'd better hope you're going to score that next inning so he can close it out," Yost said. "If you don't score, then he has to throw another three outs for you to have an opportunity. For me, it just doesn't make any sense."
Yost said it is not out of the realm of possibility to use a closer for three innings, but that would mean he would not be available to pitch again for three days.
On Wise: Instead of Cordero on Wednesday, Yost went with right-handed reliever Matt Wise, who has a 10.45 ERA since July 25 and has surrendered a run in nine of 16 appearances.
Yost was asked whether he would be able to use Wise in any more close games.
"We'll just see right now," Yost said. "He's working real hard and not having any success for his efforts. ... He's not throwing the ball good, throwing it like he has in the past."
Getting credit: Brewers stats guru Dave Lawson shies away from credit, but general manager Doug Melvin credits Lawson for keeping surprise contributor Joe Dillon on the Brewers' radar.
"The last three years, every time Dillon became a six-year free agent, Dave said, 'We should sign this guy,'" Melvin said.
Lawson, who lives in Texas and pours over statistical projects for Melvin and the Brewers, made the recommendation having never seen Dillon play. After the Marlins released Dillon in March, the Brewers signed him, and he has been surprisingly good since an August promotion to the big leagues. Dillon was batting .355 entering Thursday, when he made his fifth straight start.
Melvin said Lawson made the recommendation with a disclaimer: "I can't account for his defense." That proved prophetic on Thursday, when Dillon fell down while tracking a shallow fly ball in right field, giving the Braves a run.
Last call: FSN Wisconsin picked up the Brewers' regular season finale on Sunday, Sept. 30, at 1 p.m. CT. ... The Brewers have hit eight grand slams this season after hitting none last year, tying an obscure record. The only other team to hit at least eight after being shut out the previous year were the 1938 Washington Senators. ... The Brewers faced a non-divisional opponent on Thursday for the first time in 22 games. They went 13-8 during a 21-game run against National League Central foes.
Coming up: The Brewers will continue their four-game series with the Braves at Turner Field on Friday night at 6:05 CT. Carlos Villanueva (8-4, 4.11 ERA) will start against Atlanta's Tim Hudson (16-8, 3.33 ERA).