Costello was found dead in a hotel room in New Zealand on Monday morning, according to officials with the Auckland Tuatara, the winter league team to which Costello belonged.
Costello, who was born in Hartford in 1996, played college ball at Central Connecticut State University.
Considerations had been raised when Costello failed to fable for follow Monday, days sooner than Tuatara's opener of the 2019-20 season.
Auckland's press release has claimed that preliminary indications are that Costello died of natural causes; however, nothing has been officially determined at this time.
"It is with great sadness that we report the passing of Auckland Tuatara third baseman Ryan Costello overnight in Auckland", the statement read. In July 2018, he was traded to the Minnesota Twins and assigned to the MIracle.
Both the Fort Myers team and Pensacola team also shared their grief over his death on Twitter.
Hickey, who coached Costello for three years, said that managing him was a challenge and that coaches always remember those players. "Our thoughts and prayers go out to his family and the entire Twins organization". His home speed helped own the Miracle to the FSL Championship in 2018.
For the last year-and-a-half, Costello has been a part of the Minnesota Twins' organization.
His former minor league team in Florida tweeted, "We were very sad to learn the news about the passing of former Miracle infielder Ryan Costello this morning".