The 21-year-old defenseman will need 3-4 months to recover from surgery on his left ankle, which he fractured Saturday against the Florida Panthers.
Carlo was removed from the ice on a stretcher during the third period of the 5-1 win after falling awkwardly along the boards.
"The whole group felt bad for him watching him go off on a stretcher," Boston coach Bruce Cassidy said Sunday. "… It's disappointing for him. He's a well-liked guy on this team, done a lot. That's disheartening."
Carlo had six assists and was plus-10 with an average of 19:14 of ice time in 76 games. He played 82 games last season, his first in the NHL but did not participate in the Stanley Cup Playoffs after sustaining a concussion in the final regular-season game.
Boston has clinched a playoff berth and leads the Atlantic Division.
