The center signed a seven-year, $77 million contract with Toronto on July 1, leaving the New York Islanders as a free agent.
"He's fun to watch, and fun to be out on the ice with. He's creating a lot," Maple Leafs forward Josh Leivo told the Toronto Sun. "He had a couple of weeks off (after getting married Aug. 4), so he's looking to get back into things, but he's always looking great."
Tavares scored during a scrimmage on minor league goalie Kasimir Kaskisuo.
"Yeah, he's good," Kaskisuo said. "He owned the puck out there."