Michael McMahon

Ryan Costello is shown here in Keene in June 2017, shortly before signing a professional contract with the

Seattle Mariners.

The Keene Swamp Bats are mourning the loss of a former standout player, Ryan Costello, 23, who was found dead in his hotel room in Auckland, New Zealand, Monday morning.

Costello, a member of the Minnesota Twins organization, was preparing to play winter ball with the Auckland Tuatara in the Australian Baseball League and had been in New Zealand for only a few days. According to the Twins website, preliminary indications show Costello died in his sleep, of natural causes.

Swamp Bats President Kevin Watterson said Monday that Costello was a solid player with outstanding character. “He was a great kid. He really fit in well here and was terrific to be around,” Watterson said.

He added that Costello was on track to make the Major Leagues, showing both power and versatility in his rise through the minors.

A native of Wethersfield, Conn., Costello played a full season with the Swamp Bats in 2016 and started the season in Keene in 2017 before he was taken in the 31st round of the Major League Draft by the Seattle Mariners. He signed with Seattle after his junior season at Central Connecticut State University.

Costello was on the field in Hartford, Vt., preparing for a Swamp Bats game against Upper Valley, when he learned he had been selected in the draft.

“I didn’t know what to do,” Costello told The Sentinel. “I’m at some random field in Vermont. It really was just so overwhelming because it is something that I have worked really, really hard for my entire life.”

He was with the Seattle organization for only a year, when in July 2018 Costello and Chase De Jong were traded to Minnesota for pitcher Zach Duke. That September, Costello hit a three-run homer to help Fort Myers win the Florida State League title in high Class A. Last summer he split time between Fort Myers and Double A Pensacola, hitting .223 with 15 home runs and 46 RBI in 108 games.

“I have been an underdog the whole way,” Costello told The Sentinel shortly after he was drafted. “Even being on this team in Keene with kids from Georgia, Louisville, Virginia ... that’s an honor for me. I wasn’t a highly touted guy out of high school. UConn didn’t even take a peek. I have a chip on my shoulder because of that. I wasn’t happy about it; I wanted that attention and I wasn’t getting it. I’m not a freak athlete, I just had to work harder.”

Costello, a left-handed batter, was signed by the Tuatara in September. “Costello will be huge, because he can play all over the field — first base, third base, as well as left field and right field,” Manager Steve Mintz told Newshub New Zealand at the time.

The Tuatara said in a statement Monday that Costello’s teammates were “naturally devastated” by the news of his passing. “The Tuatara express their deepest condolences to Ryan’s family back home in the United States and to the whole Minnesota Twins organization,” the club said.

In Keene, Costello hit .264 in 2016 while playing mostly third base. He had five homers and 19 RBI and was a mainstay in the middle of the Swamp Bats’ lineup, playing a team-high 42 games. He returned in 2017 and played four games before leaving to sign with Seattle.

The Swamp Bats released a statement Monday afternoon that said: “The Keene SwampBats are saddened to learn of the untimely passing of Ryan Costello. Our entire organization and the greater Keene, NH community send their sincere condolences to Ryan’s family, friends, and the countless teammates he has played with. ... As Ryan Hadley, Ryan Costello’s host family Dad stated, “Ryan said often to my son Reid that he would be watching him in Fenway Park someday. He was family to us and always will be.”

After graduating from Wethersfield High School in 2015 as an All-Conference and All-State selection, Costello started 34 games as a freshman at Central Connecticut. He tied a single-season record with 22 doubles and hit a league-leading nine home runs in his freshman season.