Ben Sheets was put on the 15-day disabled list by the Milwaukee Brewers on Saturday with a torn back muscle and might miss the rest of the season. Sheets left Friday's game against Atlanta in the eighth inning with what the Brewers said was a strained upper back. He awoke Saturday with discomfort and had an MRI exam, which revealed a tear of the latissimus dorsi, a muscle in the upper back that moves the shoulder. Brewers team physician Dr. William Raasch said the injury typically requires four weeks to two months to heal. "There's a lot of swelling," Raasch said. "We can't tell you how quickly he'll heal. Best-case scenario is 15 days, if he's feeling great. Worst case, two months."