Manager Ozzie Guillen, who hinted at the move in recent days, said Saturday he couldn't wait any longer for the struggling Bell to correct his problems.
"Right now, we are going through a tough time," Guillen said. "It happens to the best of them. We are going to move him down for maybe a few days. It's not like we are removing him from the job. ... I made it very clear, it's not a punishment."
A three-time All-Star, Bell blew his fourth save in seven opportunities Friday night when he allowed the San Diego Padres to tie the score at 8 with a run in the ninth inning. Miami eventually won its fourth straight game on Omar Infante's RBI double in the 12th.
Bell, who signed a $27 million, three-year contract with Miami in the offseason, was not surprised by the decision and said he understood it.
"Bottom line, I am not doing the job," he said. "It's not like I am hurt or anything. But I have to figure this out and get better. I owe that to everyone in here."
Bell is 0-3 with an 11.42 ERA in 11 games. The right-hander has allowed 15 hits in 8 2/3 innings with 10 walks and only six strikeouts.
Guillen said he is not yet ready to throw in the towel on Bell, whose 132 saves for the Padres the past three seasons led the majors.
"I have the faith that he will come up out of this and he will be back to what he is," Guillen said. "I don't think he's that far away. This guy has been the best closer in the game for the last three years, numbers wise."
Bell's new role is not yet known, but Guillen said he might be used anywhere from the sixth to the eighth inning.
Miami will not immediately move any one pitcher into the closer's role, in part because the bullpen has been overused recently. Six relievers combined to throw 9 2/3 innings Friday night when starter Josh Johnson got knocked out in the third inning.
Guillen said he is "leaning" toward Steve Cishek to fill Bell's role but Cishek, who pitched three shutout innings to pick up the win Friday night, will not be used until at least Tuesday because he has thrown five innings over the past three days.
"I think this kid has shown everyone how effective he can be," Guillen said. "I think he's ready to help out in that role when we need him."
The 25-year-old Cishek is 4-0 with a 0.63 ERA in 13 games. The righty has struck out 15 while allowing just seven hits in 14 1/3 innings. Cishek has three career saves.
When Guillen was asked which pitchers were available in the bullpen for Saturday night's game against the Padres, he joked, "Mark Buehrle. He's making all that money, earn your money and go nine innings."
The Marlins optioned outfielder Bryan Petersen and LHP Dan Jennings to Triple-A New Orleans and recalled right-handers Chris Hatcher and Sandy Rosario from their top farm club. Petersen was hitless in four at-bats since he was recalled with Jennings from New Orleans on Monday. Jennings appeared in two games, allowing one hit in 1 2/3 innings.