The biggest surprise in camp, Alejandro De Aza, has won the Marlins' center-field job.
The 22-year-old De Aza played 69 games at Double-A Carolina last season, and now the speedy Dominican Republic native will be the lone rookie position player starting on the Marlins' Opening Day lineup.
"Alejandro De Aza is going to be our center fielder," manager Fredi Gonzalez said on Wednesday morning. "He plays the game the right way, and I'm very happy for him. I'm very happy for our club, too."
De Aza is batting .350 (14-for-40) with four doubles, two triples and four RBIs this spring. He tripled in three at-bats in Wednesday's 1-0 win over the Nationals.
The Marlins intend to make the jump to the big leagues go as smoothly as possible for De Aza, who will bat eighth. Gonzalez noted that against tough lefties, the lefty-hitting center fielder may not be in the lineup.
Gonzalez already has thought through a scenario where if De Aza had to face Mets hard-throwing lefty closer Billy Wagner, the Marlins may opt for a pinch-hitter.
"We sat him down and I told him, 'I don't want you to go out and hit .380. ... Go out and play your game and play the way you're playing. If we need you to carry us for a month, we're in trouble.' I said, 'Let the other guys worry about driving in runs and winning ballgames. You just go out there and play your game, and go from there.'"
When Gonzalez broke the news to De Aza early Wednesday morning, the 22-year-old was visibly nervous. Gonzalez had thought about kidding with him, but quickly decided to tell him he would be the starter.
"I brought him in and closed the door, and it was just him and me in there," Gonzalez said. "I let him know right away, because I didn't want it to linger because he was nervous. When I told him, he was excited, like he should be. This is something he always hoped for and dreamed for, and he should be.
"I was going to mess with him a little bit, but when he came in, he was so nervous, the poor kid."
All spring, De Aza has worn No. 68, but he is changing that to No. 7.
"Sixty-eight is a Spring Training number," he said jokingly.
Why No. 7, which was just vacated when first-base/infield coach Perry Hill retired?
"It was the lowest number left," he said.
De Aza said the first reaction he had when he was awarded the job was, "Wow."
With De Aza securing the center-field spot, the Marlins have filled in their two biggest Spring Training needs. On Monday, they acquired Jorge Julio from Arizona for Yusmeiro Petit. Julio will take over as the team's closer.
De Aza won the job over Eric Reed and non-roster invitee Alex Sanchez.
"I didn't know [anything], because [all three of us] were doing the job," De Aza said. "When he told me that, I was like, 'Whoa, thank God.' I said, 'Whatever happened, it was fine with me.' I was surprised."
When De Aza is in the starting lineup on Opening Day, it will be the second time he will be at an MLB game. In 2003, when he was in the Dodgers' Minor League system, he went to a Marlins-Dodgers game at Dolphin Stadium.
Reed also enjoyed a strong spring, batting .351. Sanchez was batting .163 (7-for-43).
The team did factor in concerns about De Aza making the jump to the Majors without a substantial amount of Double-A experience.
"Obviously, we took that into account, and we've done that here before," Gonzalez said. "He's not going to have concerns. I'm going to have all the concerns. We're going to bring him around easy, and let him do all the little stuff."
Also on Wednesday, the Marlins released Sanchez, reliever Felix Rodriguez and reliever Mike Koplove. Koplove had a stipulation in his contract that he could opt out by a certain date, and he did.
Reed has been optioned to Triple-A Albuquerque, while catcher Paul Hoover, pitcher Roy Corcoran and infielder Zach Sorensen have been reassigned to Minor League camp. Hoover, Corcoran and Sorensen, however, will remain in big-league camp and make the trip to Dayton, Ohio, on Saturday when the Marlins face the Reds in their final exhibition game.
The roster is now close to being set. Gonzalez said the team will use a platoon situation in right field, with switch-hitter Joe Borchard playing against right-handed pitching and Cody Ross the choice against lefty pitching.
Ross also is a platoon option in center field, although there is a commitment to use De Aza against righty and lefty starters.
De Aza is now the second Rule 5 Draft player in the Marlins' starting lineup. He was a Minor League Rule 5 choice for Florida in 2004. Second baseman Dan Uggla was taken in the Major League phase of the 2005 Rule 5 Draft.
As for the other roster moves made on Wednesday, Rodriguez was a non-roster invitee who was 1-0 with a 1.64 ERA in 11 games.
"They told me I pitched good, but I was not on the 40-man roster," Rodriguez said. "I'll now look for something else."
Asked if he would eventually go to Triple-A for the Marlins, Rodriguez said: "I don't know."
One reserve spot is still up for grabs, with infielder Jason Wood battling outfielder John Gall.
Backup shortstop Alfredo Amezaga remains an option to play in the outfield, but the team is trying not to have the switch-hitter play center.
The bullpen will open the season with Julio, Matt Lindstrom, Kevin Gregg, Henry Owens, Renyel Pinto, Randy Messenger and either Nate Field or Lee Gardner.
The rotation will feature Dontrelle Willis, Scott Olsen, Anibal Sanchez, Ricky Nolasco and Sergio Mitre.
Because of an off-day on April 5, Mitre's first start will be on April 10 at home against the Brewers.
Injury update: Reliever Taylor Tankersley and right fielder Jeremy Hermida have been told they will open the season on the disabled list, retroactive to March 23. Tankersley has been recovering from shoulder inflammation and Hermida is out with a deep bone bruise to his right kneecap.
The team has yet to officially place them on the DL, but both will be eligible to be activated on April 7.
Right now, Field and Gardner are competing for the bullpen spot that will be open while Tankersley is on the disabled list.
Joe Frisaro is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.