MIAMI -- Jonathan Villar played in all 162 games with the Orioles last season, and he impacted games with his power and speed. The switch-hitting 29-year-old connected on 24 home runs and stole 40 bases.

Much of the Marlins' planned upgrade to their offense depends on keeping Villar in the lineup.

A few days ago, Miami received a mild scare when Villar complained of back spasms.

The Marlins had their final Summer Camp workout on Monday at Marlins Park, and Villar worked at second base.

Villar projects to be the Opening Day center fielder.

“You know you want him in there offensively all the time,” manager Don Mattingly said. “The back thing kind of gave him a little setback, as far as getting a little bit more time in center field.”

Along with center field and second base, the Marlins are open to using Villar occasionally as the designated hitter.

“We’ve got to keep him healthy,” Mattingly said. “If I have to DH him some early to make sure he’s good with his back and all that kind of stuff, that’s what we’ll do.”

Foremost for the Marlins is having Villar in the lineup, where he’s expected to lead off. A year ago, his slash line was .274/.339/.453 with 73 RBIs and 111 runs.

“I look at Jonathan as a ‘game guy,’” Mattingly said. “If you’re going to watch Jonathan take BP, and stuff like that, he’s not that guy.”

When games are being played, that’s when Villar kicks it up a notch.

The way the Marlins have been practicing, it appears that if Villar isn’t in center field, prospect Monte Harrison could handle the position.

Miami’s No. 9 prospect per MLB Pipeline, Harrison has enjoyed a strong Summer Camp. He’s not yet played in the big leagues, but he has made the case to be part of the 30-man Opening Day roster.

If Harrison shows that he’s ready to play on a regular basis, that frees up Villar to play either in the infield or DH.

“We see [Villar] in center, and we see him in the infield,” Mattingly said. “We see some DH days in there, to keep him fresh. I want to keep him in the lineup as much as I can.”

Time is now
Many insiders are predicting the Marlins to finish last in the National League East. The organization has other ideas.

Shortstop Miguel Rojas, the unofficial team captain, has bought into the building process the past two years. Even though the club finished last in each of those seasons, Rojas feels the youthful Marlins are ready to make a big leap in the 60-game season.

Aside from the upgrades to the big league roster, Rojas is impressed by the wave of prospects getting close to being ready.

Infielder José Devers, first baseman Lewin Díaz, outfielder Jesús Sánchez and pitchers Nick Neidert and Robert Dugger are just a few of the prospects who impressed Rojas in camp.

“A guy like Jose Devers, I’m pretty impressed by that kid,” Rojas said of the 20-year-old. “He had the opportunity to play on a big league field and play against the big league club. He was playing short. He looks good.

“Jesús Sánchez hit a ball, one of the farthest balls I’ve ever seen a lefty hit in the ballpark. Lewin Díaz, I’m pretty excited about that guy. Nick Neidert has been looking great. Dugger has been throwing the ball really good.”

The culture being built by the veterans and younger players has Rojas excited about Miami’s future.

“Other than the starters that we have, we have a lot of talent coming behind them,” Rojas said. “It doesn’t matter if they don’t make the club right now. We know we’ve got those guys waiting for their time. And they’re going to be ready for it.”

Roster moves
The Marlins on Monday released right-handed reliever Ryan Cook and reassigned right-handers Josh A. Smith and Nick Vincent to the club's alternate training site, the Roger Dean Chevrolet Stadium complex in Jupiter, Fla. Smith and Vincent were non-roster invitees, as was Cook.

Travel roster to Atlanta
The Marlins have announced their travel roster to Atlanta for the exhibitions on Tuesday and Wednesday at Truist Park. The list includes, catchers: Jorge Alfaro, Chad Wallach and Francisco Cervelli; infielders: Isan Díaz, Jonathan Villar, Jon Berti, Sean Rodríguez, Brian Anderson, Miguel Rojas, Jesús Aguilar, Eddy Alvarez, Lewin Diaz, Jazz Chisholm and Jose Devers; outfielders: Corey Dickerson, Garrett Cooper, Magneuris Sierra, Harold Ramirez, Monte Harrison and Jesús Sánchez; right-handed pitchers: Sandy Alcantara, Brandon Kintzler, Brad Boxberger, Jeff Brigham, Pablo López, Ryne Stanek, Sterling Sharp, Elieser Hernandez, Nick Neidert, José Ureña, Robert Dugger, Drew Steckenrider, Jorge Guzman, Jordan Holloway, Aaron Northcraft and Yimi García; left-handers: Caleb Smith, Stephen Tarpley, Adam Conley and Alex Vesia. The list of players going to Atlanta is not necessarily the Opening Day roster.

Up next
After concluding Summer Camp, the Marlins will head to Atlanta on Tuesday morning to face the Braves at 7 p.m. ET at Truist Park in the first of two exhibition games. On Tuesday, right-hander José Ureña will start for Miami. Mike Foltynewicz gets the nod for Atlanta. And on Wednesday, Pablo López will take the ball for the Marlins against Kyle Wright, at 4 p.m. Both games are being televised by Fox Sports Florida.