Turnbow saved 63 games for the Brewers from 2005-2006, but struggled mightily with command this season and fell to the bottom of the depth chart, appearing mostly in games the Brewers trailed.
He has a 15.63 ERA and has walked at least one batter in all eight of his appearances.
"It's obvious why we did it," manager Ned Yost said. "His production had fallen off to the point that it was hard to find spots to use him."
Yost said Turnbow needed a change of scenery, and that didn't necessarily mean a change of organization.
"You have to get away and catch your breath first," Yost said. "Then you get your confidence back. ... When you're struggling with confidence a little bit, everything compounds it."
The Brewers have 10 days to trade Turnbow, release him or pass him through waivers and assign him to the Minors. Given his $3.2 million salary, a trade would be difficult, and the Brewers seem intent on not releasing Turnbow and paying the roughly $2.65 million left on his contract.
That leaves the final option as a possibility. The Brewers have until Day 7 of the 10-day window, which began Friday, to place Turnbow on irrevocable waivers, a necessary step if they try to assign him to Triple-A Nashville. Any of the 29 clubs could claim Turnbow and pay him a prorated portion of the Major League minimum -- $400,000 -- leaving the Brewers on the hook for the rest.
If Turnbow clears waivers, he could refuse the assignment, though he would forfeit his salary. Or, he could report to Nashville as the team's new closer.
Turnbow's agent, Rick Thurman, did not return a telephone message Friday afternoon.
Count Brewers pitching coach Mike Maddux among those hoping Turnbow makes it through.
"I think the best medicine for Derrick is to get in a different environment and get it right," Maddux said. "Hopefully, he's still with us and can come back and help us."
Maddux believes Turnbow would benefit from some time in a closing role.
"It wasn't physical as much mental," Maddux said. "So far this year, his best outing was when he was closing. The mentality of closers, few people have it."
Melvin said he fielded a few Friday morning calls from fellow GMs regarding Turnbow.
He's open to a trade that lands Turnbow in the Major Leagues, and promised the pitcher as much on Thursday night.
"But I'm also not going to give him away," Melvin said. "If somebody says, 'I don't want to take on any money and I don't want to give up any players,' that's giving him away. I don't have a problem with playing him in the Minor Leagues. It's not like you're taking on more money."
Turnbow's big hair, high-90s fastball and off-the-scrapheap back story made him a Brewers cult hero in 2005, when he tied a franchise record with 39 saves. He started hot in 2006 and gave Milwaukee a blue-collar representative to the National League All-Star team.
Nearly two years later, much of the love has vanished along with Turnbow's fastball command. He appeared to turn a corner last week against the Phillies, when Turnbow filled in for regular closer Eric Gagne and recorded his first save in a calendar year.
He was unable to build on that success. Turnbow loaded the bases on a hit and two walks without recording an out April 27 against the Marlins, then surrendered four hits, four walks and six runs on Wednesday against the Cubs. The Brewers were already in a 13-5 hole when Turnbow entered the latter game.
"He was given a couple opportunities," Melvin said. "I told him, 'We don't have enough games to be able to do that. It's not fair to Ned to try to continue to work to find you a spot, and it's not fair to you to have to work on something when all these games have been close games.'"
The Brewers made their decision on Thursday, before the Brewers played their series finale against the Cubs. But Melvin and Yost did not want to break the news at Wrigley Field, because the Brewers had just scored an uplifting win, and the cramped visitor's clubhouse was filled with reporters and cameras.
So they sat down with Turnbow after the team arrived in Houston. He was not particularly surprised, according to Melvin, and returned to Milwaukee on Friday morning to meet his wife and young son.
Turnbow, 30, is in the final season of a three-year contract. He has one year of arbitration eligibility remaining before he's a free agent.