Franklin was 1-4 with an 8.46 ERA and one save in 16 games. On Tuesday night against the Baltimore Orioles, the 38-year-old righty gave up two runs and three hits, including a homer, while getting only one out.
His inability to be effective, even in a mop-up role, led to the Cardinals giving him his unconditional release.
"It just came to a tipping point," general manager John Mozeliak said at Camden Yards before the Cardinals faced the Orioles.
"We tried to give him an opportunity to get back on track -- multiple opportunities -- but unfortunately it just wasn't working out," Mozeliak said. "We felt what was best for him personally and for the organization that we make this decision. Obviously, he was disappointed that it came to this for multiple reasons, but I also think he felt somewhat relieved."
The Cardinals intended to play with a 24-man roster on Wednesday night. They will add another player on Thursday, Mozeliak said.
Franklin had been with the Cardinals since 2007, going 20-15 with a 3.04 ERA. Last season he was 6-2 with a 3.46 ERA and 27 saves. He had 38 saves in 2009 and was on the NL All-Star team.
This year, however, Franklin struggled from the outset. He lost the closer's job in April and then lashed out at St. Louis fans after they booed him for giving up a home run. Franklin later apologized, saying he was "frustrated with myself."
Manager Tony La Russa said Wednesday, "The fans should know that if something didn't work and they are upset, he's more upset than any of us put together."
In his final four appearances with the Cardinals, he yielded nine earned runs and 14 hits -- including five homers -- over six innings.
"He goes and does it then all of a sudden makes a mistake. It's incredible," La Russa said. "He's suffering more than anybody."
Instead of sending Franklin to the minors, Mozeliak opted to cut ties completely.
"We thought it was better to split with the team altogether," Mozeliak said.
Franklin broke into the majors with the Seattle Mariners in 1999 and played with the Philadelphia Phillies and Cincinnati Reds in 2006 before signing as a free agent with the Cardinals before the 2007 season. He had 83 saves with St. Louis in 264 games through last year and impressed La Russa with his will to win.
"He's not one of those guys that when something happens says, 'What's the big deal?' He's been a core contributor," La Russa said.
Franklin owns a career mark of 62-76 with a 4.14 ERA with 84 saves in 532 games.