The between-innings entertainment team, known as the Manatees, is comprised of a dozen men who responded to an ad seeking "the biggest bellies with the biggest jiggle" and "the biggest feet with the best dance moves," The Miami Herald reported Monday.
The dancers, who are set to make their debut during Monday's home opener against the New York Mets, have been training for one month.
For the team's senior member, Abraham ''The Big Rev.'' Thomas, 61, who has six grandkids, the team meetings leave him sore for days.
"After practice, I have to stay in bed for at least a day. I sleep with oxygen," said Thomas.
Gabe "McLovin'" Esquijarosa, 25, agreed that the training was difficult.
''If they make us keep this up, we won't qualify for next year's squad,'' he said. "'I secretly think this is a plan by some TV show to get us to lose weight -- you know, `the Marlins reaching out to the community' or something like that."