"I stunk in April, plain and simple," Bell said. "I said I stunk, I worked hard, I busted my butt. I think I've had a tremendous second half. I'm not closing -- I know that. But I just kept my mouth shut because I want to regain what I had, and I feel like I can't do that."
Marlins catcher Brett Hayes rallied to Guillen's defense on Twitter later Monday.
"If you don't feel like @OzzieGuillen has your back as one of his players," Hayes tweeted on his account, @BrettHayes9, then "clearly you don't pay attention."
In April, Bell was 0-3 with a 10.80 ERA in eight games. He was 2-5 in save chances in the month.
In the first half, Bell was 2-for-5 with a 6.75 ERA, saving 19 of 25 chances. His first half ended on a sour note. On July 8, Bell let a two-run lead slip away in the ninth inning at St. Louis.
When the second half started, Guillen turned to Cishek to close.
Used mostly in setup situations in the second half, Bell's numbers have improved since the All-Star break. The right-hander is 1-0 with a 3.12 ERA in 29 games.
He's had one save chance in the second half. On Sept. 8 at Washington, after a rain delay, Bell entered trying to preserve a one-run Miami lead. But he surrendered a leadoff homer to Jayson Werth, for his seventh blown save of the season. The Nationals won in extra innings.
Bell, however, has been solid in September. In 10 appearances in the month, he has a 1.00 ERA.
The last-place Marlins have been the subject of a lot of rumors and media attention since they started their final road trip of the season.
There has been widespread speculation surrounding the front office and Guillen. Last Friday, team owner Jeffrey Loria informed president of baseball operations Larry Beinfest, and the rest of the front office, that there would be no changes after the season.
On Sunday, Guillen met with Loria in New York.
"It's been an interesting year with Ozzie," Bell said.
The Marlins start their three-game series with the Braves on Tuesday at Turner Field.