Obtained from the Angels for reliever Chris Resop last November, Gregg is a 28-year-old with 125 games of big-league experience.
That bit of Major League service time is giving him an early edge for Florida's unsettled closer situation.
Ideally, the club wants someone big-league battle-tested to replace Joe Borowski, who parlayed a 36-save 2006 into a free-agent contract with the Indians.
Gregg, who has been a starter and long reliever, is in the closer mix with Taylor Tankersley, Henry Owens and Matt Lindstrom.
"Everybody aspires to be either a closer or starter," said Gregg, a 6-foot-6, 238-pound right-hander. "You want to work in the back end to pitch in the seventh, eighth or ninth inning. I've been blessed over the last couple of years to watch guys like Troy Percival, Francisco Rodriguez, Scot Shields and Brendan Donnelly. Those are some of the premier guys in the game. I've been fortunate to watch them a couple of years."
Because of the depth the Angels had, Gregg found himself logging innings in a long-relief or spot-starter role. He appeared in 32 games a year ago and worked 78 1/3 innings, striking out 71 while walking 21.
His fastball is clocked between 91-94 mph, and he mixes in a sinker and slider.
From his days with the Angels, he witnessed firsthand how talented relievers went right after hitters.
"Along with all of their abilities, they like to attack hitters," Gregg said. "They put hitters on edge. They never pitch timid. They believe in their stuff and that they are going to get guys out.
"They've got good stuff. At this level, a lot of people have good stuff, but you have to believe in what you have. That's what they do. They believe in what they can do and they attack people."
Closing, though, would be a new role for Gregg. He doesn't have a big-league save, and he logged just one save in his Minor League career.
"Baseball is a game of opportunity," he said. "We have an unbelievable starting staff here. I like the idea of going to the back end of the bullpen and pitching in 60-70 games."
Health update: Anibal Sanchez, working to regain the strength in his shoulder, threw off the mound Friday.
Manager Fredi Gonzalez says Sanchez is close to pitching against hitters in batting practice.
"No news is good news," Gonzalez said. "Usually [bad] news filters down. But [pitching coach] Rick [Kranitz] said everything was outstanding. He will be ready to throw BP in the next day or two."
Gonzalez said Sanchez is about "four or five" days behind the rest of the pitchers. The plan is to get the right-hander caught up quickly once the games begin.
Josh Johnson, meanwhile, will throw off flat ground again on Saturday.
Johnson took Friday off from tossing a day after he wasn't feeling entirely right after a throwing session.
Johnson has been battling through some discomfort in his right triceps area, which has bothered him since January.
He threw Wednesday and Thursday, took Friday off, and will be back tossing Saturday.
Getting game ready: Full-squad workouts are a time to stress fundamentals, but Gonzalez says the players are getting antsy for the games to begin.
On Tuesday, the Marlins get their first game action against the University of Miami Hurricanes, who visit Roger Dean Stadium for a 3:05 p.m. ET start.
Florida's Grapefruit League schedule begins the next day, also at Roger Dean Stadium, when the Fish are the visitors against the Cardinals. That game starts at 1:05 p.m.
Gonzalez said he will announce the pitchers for the University of Miami game, as well as setting an early schedule for his pitchers, on Saturday.
The position players are expected to get at least one at-bat, and perhaps two, against the Hurricanes.
Cabrera working on his defense: Offensively, Miguel Cabrera is among the elite hitters in the game. Defensively, the 23-year-old feels he should also improve now that he has one full season at third base under his belt.
Groomed as a third baseman in the Minor Leagues, Cabrera played mostly left field from 2003-05. In 2004, he worked in right field in the early part of the season.
Overall, Cabrera has appeared in 220 big-league games at third base, compared to 347 in the outfield.
An area he expects to improve on is his throwing to first base.
"I think I'm going to do better. I played about 30 or 40 games [at third base] in Venezuela," he said, referring to Winter League action. "I feel I'm going to be more comfortable making better throws to first base. That was harder for me, throwing to first base, after I [switched from left field]. Now, I have better throwing angles to first base."
Joe Frisaro is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.