The Maple Leafs made the announcement, saying Tavares will return to Toronto for evaluation. His status for Team Canada is uncertain. Canada opens play in the world championships on Friday against Finland.
The world championships run through May 26.
Tavares, 28, had 47 goals and 41 assists while playing all 82 games this season, his first with the Maple Leafs after signing with Toronto as a free agent.
He also played all 82 games in 2017-18, his final season with the New York Islanders.
The six-time All-Star has 272 goals and 349 assists in 10 NHL seasons.