The A's released left-handed reliever Brian Fuentes on Wednesday, eight days after the club designated the four-time All-Star for assignment.
Unless another team claimed Fuentes off waivers, Oakland had 10 days to work out a trade with another team. Instead, Fuentes will be a free agent, and can sign with any organization.
The 36-year-old is making $5 million this season in the last year of a two-year deal, and had a $6.5 million team option for 2013, with a $500,000 buyout.
Fuentes spent time as the A's closer this season and earned five saves, including the 200th of his career. He posted a 2.84 ERA over his first 19 appearances, but that mark swelled to 19.50 over his last seven outings, with two blown saves and two losses.
With Fuentes struggling and dealing with a minor right ankle injury, manager Bob Melvin called him to the mound only twice in the last 18 days before he was designated.
"I'm not really that surprised," Fuentes said. "It's just not really a good fit for me right now. It's unfortunate. It wasn't for lack of preparation. I was just pitching inconsistently, and it put Bob and the upper management in a tough situation, because they're trying to develop some guys and they can't wait for me forever.
"I think it's best for everybody involved. It gives me a chance to go somewhere and pitch."
Fuentes has played for five teams in his 12-year career, compiling a 3.58 ERA and 204 saves in 608 1/3 innings. He notched a 3.70 ERA in 58 1/3 innings for the A's last season.
Andrew Simon is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.