Marlins’ Dan Castano was a pleasant surprise in 2020. Can he carve out a role in 2021?

Dan Castano had thrown maybe two warmup pitches in the Yankee Stadium visitor’s bullpen on Sept. 27 when he was called into action.

Jose Urena, the Miami Marlins’ starting pitcher for their regular-season finale, was removed from the game after suffering a right forearm fracture in the third inning on a ball hit back to him by D.J. LeMahieu.

The moment turned into Castano’s biggest performance of his early MLB career and perhaps served as an impromptu audition for how he could be used in the 2021 season.

Castano, an unassuming 26-year-old left-handed pitcher, mowed down one of the league’s top offenses for a career-long 6 1/3 shutout innings out of the bullpen that day, giving up just four hits and two walks while striking out two. The Marlins, already playoff bound for the first time in 17 years, won that game 5-0 to secure their first winning season since 2009.

“I didn’t have the time to think,” Castano said last week, reflecting on the win. “[The coaches] were like ‘How do you feel? Do you want one more?’ I was like ‘Sure.’ The next inning, ‘Do you want one more?’ ‘Absolutely.’ It kind of went on like that for five or six innings. Next thing you know, I look up and it’s the ninth and we got a win.”

It was the final big moment of Castano’s under-the-radar season.

Castano wasn’t the flashiest name among the 18 Marlins players who made their MLB debuts last season. He was never a top-30 prospect in the organization. He doesn’t have the pure stuff of fellow pitchers Sixto Sanchez and Trevor Rogers or the pedigree and high ranking of position players Jazz Chisholm, Lewin Diaz, Jesus Sanchez and Monte Harrison.

But the lack of fanfare didn’t stop Castano from quietly putting together a solid first MLB season and putting himself in position to carve out a full-time role for the Marlins in 2021 depending on how the rest of the offseason unfolds.

With the Marlins loaded with top-end starting pitching talent, Castano faces an uphill battle to be part of the big-league rotation but he could find himself carving out a role as long-reliever out of the bullpen, a role the Marlins struggled to fill last year. They tried a slew of players in the position in 2020 — from Robert Dugger to Nick Neidert to Brandon Leibrandt to Jordan Yamamoto — to varying degrees of success.

“Daniel is not getting all the attention of Sixto and all the top prospect guys, but this guy has really thrown the ball well,” Marlins manager Don Mattingly said after that Yankees game. “He’s really shown himself all year long, and he’s a little bit of a surprise, honestly.”

Castano made seven appearances (six starts) in the pandemic-shortened 2020 season, with his final four starts coming on days the Marlins played doubleheaders. He posted a 3.03 ERA over 29 2/3 innings and held opponents to a .263 batting average and a 1.38 WHIP (walks and hits per inning pitched). Sanchez, the Marlins’ top prospect, was the only rookie pitcher on the team to throw more innings in 2020 than Castano.

“For me, personally, it’s reassuring to know that I can pitch at the big-league level, to have some success and to have teammates that are going to have your back,” Castano said. “You’re not just sitting out there on an island. Sometimes, people say the mound can be one of the loneliest places, but when you have support from your teammates, especially as a younger guy, it’s really reaffirming.”

And while Castano may not stand out from a pure stuff standpoint (his four-seam fastball averaged 89.4 mph last season, which ranked in the bottom 8 percent per Statcast), he had success.

▪ Castano’s 3.03 ERA was better than that of Sanchez (3.46) and Rogers (6.11), ranked as the Marlins’ Nos. 1 and 9 prospects by MLB Pipeline and the only other Marlins rookie starting pitchers to have seven apperances last season.

▪ The Marlins went 4-3 in Castano’s 7 games compared to 3-4 marks for both Sanchez and Rogers in the regular season. Miami won each of Castano’s final four games. He had a 1.42 ERA (three earned runs in 19 innings pitched) in those outings.

▪ Castano only allowed hitters to post a .270 batting average on balls in play. Opponents had a .303 BABIP against Sanchez and .380 mark against Rogers. That low mark was essential for Castano’s success considering his low strikeout rate (just 12 over 29 2/3 innings).

Not bad for a player who was considered to be nothing more than a throw-in piece from the Marcell Ozuna trade with the St. Louis Cardinals in December 2017 that netted the Marlins Sandy Alcantara, Magneuris Sierra and Zac Gallen (who was traded in 2019 to the Diamondbacks for Chisholm).

“It just gives me confidence,” Castano said. “We have a lot of really good pitchers and really good young guys. I know they’re all working really hard as well. We get together as a team. We all push each other. We watch film together. We talk about strengths and weaknesses. ... You hope for the best and you work to win.”

The Marlins had some success in 2020, going 31-29 and reaching the National League Division Series. They want to go farther in 2021.

“We enjoyed last year. It was great,” Castano said. “But we weren’t happy. Only one team gets to finish happy at the end of the year. We enjoyed our time in the playoffs, but we definitely want to be that last team standing in the near future.”