Team USA announced multiple changes to its preliminary world junior roster on Sunday.

The roster remains at 29 players, but defensemen Tyler Kleven and Hunter Skinner, along with netminder Logan Stein, will replace forwards Robert Mastrosimone, blue-liner Alex Vlasic, and goaltender Drew Commesso, who have each been deemed "not available to participate."

Vlasic, Commesso, and Mastrosimone all play at Boston University. The school suspended all activities for the men's hockey team Thursday and canceled its season opener after someone associated with the program tested positive for COVID-19.

"It’s certainly heartbreaking for Robert, Alex, and Drew to not have the chance to make our team and we feel for them," general manager John Vanbiesbrouck said.

"But it’s great to have the depth we do and we’re pleased to welcome Tyler, Hunter, and Logan. We’re excited to get our camp underway and continue to work with our medical staff, the IIHF, and the government of Alberta to help provide the safest possible environment for everyone associated with our team."

Team USA started its week-long camp Sunday at USA Hockey Arena in Plymouth, Michigan. The 2021 world juniors are slated to begin on Dec. 25 in Edmonton.

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