Spectators watch near an artist’s rendering during a groundbreaking ceremony for a new minor league baseball stadium, Thursday, July 11, 2019, in Worcester, Mass. Polar Park will be the new home of the Boston Red Sox’ Triple-A affiliate, beginning in 2021. The club announced last year that it is moving from Pawtucket, R.I. to Worcester after failing to reach a deal for a new stadium with Rhode Island officials. (AP Photo/Elise Amendola)

WORCESTER, Mass. — Red Sox executives joined officials from the state and the city of Worcester on Thursday to break ground on a 10,000-seat stadium for the ballclub’s Triple-A affiliate.

A crowd of about 1,000 people attended the ceremony to welcome the International League team now based in Pawtucket, Rhode Island, that is scheduled to begin play about an hour west of Fenway Park in the 2021 season. The team had announced the move last year after failing to reach a deal on a new stadium with Rhode Island officials.

“Worcester is a great baseball city,” team chairman Larry Lucchino said.

The $100 million Polar Park is planned for a lot in Worcester’s Canal District, with light post was painted yellow on Thursday to mark the future foul pole in left field. Train tracks running behind the outfield wall will give the ballpark an urban feel.

Janet Marie Smith, who has worked on 11 major league ballparks, including the renovation of Fenway Park, said Polar Park will not have a Green Monster replica in left field but will incorporate other features unique to the site.

A concession tent sold hats, shirts and blankets for the new ballpark as the PawSox mascot mingled with an actor in a 19th Century baseball uniform to recall the period (1880-82) when Worcester hosted a National League team. The city was the site of the first perfect game in major league history and it was also the hometown of Ernest Thayer and where he wrote the baseball poem, “Casey at the Bat.”

“This day is not the start of our city’s history of baseball,” said Worcester Mayor Joe Petty, who was among the dignitaries using baseball bat-shaved shovels in the ceremonial ground-breaking. “This is just one inning.”