MIAMI -- While Jeff Mathis completed his recovery process, several other Marlins continue to work their way back to health.
Giancarlo Stanton still has not performed any baseball activities, but the slugger has been running in the pool.
Stanton went on the disabled list on April 30 with a strained right hamstring trying to run out a grounder in an extra-inning win over the Mets.
"From what I've heard, it's a similar type of strain to what [Casey Kotchman] has had," Marlins manager Mike Redmond said. "It took him a while. We don't have a timeframe - it's just on how fast he heals and how fast he thinks he can get back on the field."
Logan Morrison, on the 60-day disabled list, was scheduled to play five innings at first base for the first time in extended spring training in Jupiter.
Redmond said he was progressing well. Last September, Morrison underwent right knee surgery. The earliest he is eligible to come off the DL is May 30.
According to Redmond, Kotchman, who is running and taking grounders during batting practice, is close to rehab over the "next few days."
Right-hander Nathan Eovaldi will throw 30 pitches on Thursday. Right-hander Henderson Alvarez started throwing, but is not ready for bullpen sessions.
"Hopefully getting Mathis back is a sign of things to come and get these guys healthy and back where they belong," Redmond said.
Donovan Solano, who was put on the 15-day DL on May 7 (retroactive May 6) with an intercostal strain, said he doesn't have a timeframe for his return.
Mathis joins Marlins after season-opening DL stint
MIAMI -- There was a two-week span in the spring when Jeff Mathis couldn't get off his recliner.
On Feb. 23, a foul ball off Matt Holliday's bat in the third inning of the first Spring Training game broke Mathis' right collarbone.
Mathis, who has broken his wrist and face before, said this injury was more painful.
"I guess I underestimated the lack of mobility I've had for so long," Mathis said. "When I took the sling off, it was amazing how much atrophy took place in my shoulder, and that's been the biggest grind is just getting the strength back."
The 30-year-old was reinstated from the disabled list prior to Tuesday's series opener against the Reds after rehab-assignment games for both Double-A Jacksonville and Triple-A New Orleans.
Acquired in the big offseason trade with Toronto, Mathis was expected to be Miami's primary backup catcher. The Marlins will carry three backstops for now: Mathis, Rob Brantly and Miguel Olivo.
"It's nice to be back on the field," said Mathis, who doesn't plan on wearing additional padding. "I've been playing down there [in the Minors] for about 10 days, and it's nice to be between the lines and back playing ball and participating again."
Dietrich, Ozuna get chance in heart of lineup
MIAMI -- During the spring, the most-asked question to Marlins manager Mike Redmond concerned who would hit behind slugger Giancarlo Stanton in the lineup.
With Stanton and other key cogs on the disabled list, Redmond has used a variety of different lineups, hoping to spark an offense that has produced a Major League-low 108 runs entering Tuesday.
That didn't change for Tuesday night's series opener against the Reds, as he placed rookies Derek Dietrich and Marcell Ozuna in the heart of the order -- batting third and fourth, respectively.
"We've used many combinations this year, and I'm sure you talk about it all the time and think I'm out of my mind -- and I might be -- we're looking for guys to produce," Redmond said. "It seems like all these different combinations we use seem to produce the same thing.
"We'll go with a couple of young guys in the middle of that order I know will go up there and swing the bat and see what happens."
Dietrich, 23, playing in just his fourth big league game after his callup from Double-A Jacksonville, entered Tuesday 4-for-11 with a double, home run and three RBIs.
Ozuna, 22, entered Tuesday with 12 big league starts, batting .326 (15-for-46) with five doubles, one homer and five RBIs. He is also tied for the National League lead for right fielders with three assists.
"I'm not scared," Redmond said. "They know I have confidence in them just like I do with everyone on this team. 'Go out there and have fun and take advantage of the opportunities and situations.' This is a great opportunity for everyone on that field to show what they can do and produce. We're looking for guys to produce."
Christina De Nicola is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.