JUPITER, Fla. -- After 10 days of practicing on the back fields, exhaustively reviewing the fundamentals, the Marlins switch into game mode on Saturday with their Grapefruit League debut against the Mets in Port St. Lucie, Fla.

The start of games marks the first time that fans can see newcomers like Jonathan Villar, Corey Dickerson and Jesús Aguilar, as well as some of the organization’s top prospects, like outfielders JJ Bleday, Monte Harrison and first baseman Lewin Díaz.

“You can see the present, but you can also see the future,” Marlins president of baseball operations Michael Hill said. “The biggest change is there’s just so much more talent. When you talk about building something sustainable, you want to have layers of talent. That’s something we’re most excited about.”

With games getting underway, the Marlins will get more clarity on how their position battles will shape up. Up for grabs this spring are spots at the back of the starting rotation and in the bullpen. The everyday lineup is pretty clear, but where everyone will play is expected to change. For instance, Garrett Cooper could be in right field or at first base. If center field doesn’t pan out, Villar could go back in the infield. Isan Díaz is the front-runner at second base, but he has to win his spot.

Right-hander Jordan Yamamoto is getting the starting nod for Miami against the Mets. He is competing for the Marlins' final rotation spot, alongside Elieser Hernandez, Robert Dugger and Nick Neidert. Hernandez is scheduled to start on Sunday against the Nationals, in Miami’s home opener.

In the offseason, the Marlins made several moves to upgrade an offense that ranked 29th in runs and 30th in home runs last season.

“Offensively, we just want to stick with the message of getting after it and being aggressive and forcing the action,” Hill said, "and doing everything that we can to score runs.”

Dickerson will be the new left fielder, and Villar, a career middle infielder, is switching to center field. Aguilar is a candidate to start at first base along with Cooper, who also could be in right field.

“We’ve said it,” Hill said. “There’s a tremendous amount of talent here in camp. The competition has been great. I think that’s part of guys pushing one another, and pushing them to be the best versions of themselves.”

Miami has its top eight prospects in camp, featuring pitchers Sixto Sanchez (No. 1), Edward Cabrera (No. 6), Braxton Garrett (No. 7) and Trevor Rogers (No. 8). The top-rated position players in camp outfielders Bleday (No. 2), Jesus Sanchez (No. 3) and Harrison (No. 5) and shortstop Jazz Chisholm (No. 4).

Sanchez, Chisholm and Harrison each project to start the season at Triple-A Wichita, while Bleday could open either at Class A Advanced Jupiter or Double-A Jacksonville.

Lewin Díaz, the No. 12 prospect, was acquired from the Twins as part of the Sergio Romo trade. The left-handed-hitting first baseman has impressed early in camp. He also is likely to open at Triple-A.

“It’s exciting to see some of the young prospects get to the upper levels and get into Major League camp, and show what they’re capable of doing,” Hill said. “It’s an opportunity to show our Major League staff what they’re capable of doing. We’ll have opportunity to give all these guys at-bats.”