Dustin McGowan is a middle-innings candidate who can pitch multiple frames.
With Jeff Locke (left biceps inflammation) expected to open the season on the disabled list, the Marlins are looking at Jose Urena as one long reliever who can be a spot starter.
"If you look at our bullpen with Ramos, Phelps, Barraclough, Ziegler, and Tazawa, you know what you're getting there," Mattingly said. "Those aren't your true bridge guys. If it's early, you've got McGowan and whoever else it ends up being. Those guys there, we need those guys to be multiple-innings guys. If not, you end up beating everybody up.
"We're looking for three multiple-inning guys out of those long guys."
If Cervenka makes the club, he would be the lone left-hander in the 'pen. But he wouldn't necessarily be a specialist.
"I don't think we can afford lefty specialists with what we're trying to do," Mattingly said. "We need somebody that can get righties and lefties out, is durable, bounces back and can throw multiple innings, and a day later can still do something. All those guys we think fit into that role, we're thinking about 50-60 pitches."
• Dan Straily became the first Miami pitcher to take at-bats in a Grapefruit League game on Saturday. Until this point, the club has been going with a designated hitter. But from this point forward, all starting pitchers will hit and ideally get two at-bats.
Joe Frisaro has covered the Marlins for MLB.com since 2002. Follow him on Twitter @JoeFrisaro and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.