The Islanders were one of six teams, along with the Maple Leafs, San Jose Sharks, Dallas Stars, Boston Bruins and Tampa Bay Lightning, who were invited to Los Angeles to make in-person presentations to Tavares from June 25-27. New York could have offered Tavares an eight-year contract, all other teams could offer seven.
When the deadline to reach an agreement passed at 12:01 a.m. July 1, Tavares become an unrestricted free agent and agreed to join Toronto, tweeting an accompanying photo showing him sleeping under a blue-and-white Maple Leafs blanket as a kid.
They were the team he grew up cheering for and who Lamoriello helped make attractive for free agents.
In Lamoriello's three seasons as Maple Leafs GM (2015-18), they went from last place in the NHL standings to consecutive appearances in the Stanley Cup Playoffs. Lamoriello and assistants Kyle Dubas and Mark Hunter combined to build a roster with young talent, including forwards Auston Matthews and Mitchell Marner.
When it was announced Lamoriello would not return as Maple Leafs GM, Toronto named Dubas as his replacement on April 30. Lamoriello later joined the Islanders and hired Barry Trotz, who won the Stanley Cup with the Washington Capitals, as coach on June 21.
"I think Mark and Kyle were ready as far as leadership goes," Lamoriello said. "It was [Maple Leafs president Brendan Shanahan's] decision. As for my relationship with Kyle, there was never an issue. He remains a good friend."
Tavares, who was selected by the Islanders with the No. 1 pick in the 2009 NHL Draft, had 621 points (272 goals, 349 assists) in 669 games with the Islanders and served as captain since 2013-14.
The Islanders and Maple Leafs will play against each other three times this season; Dec. 29 in Toronto and Feb. 28 and April 1 in New York.
"As I've said all along, you can't look back," Lamoriello said. "We did everything we could to convince John to come back. The only thing that matters now is pushing ahead and making the New York Islanders the best they can be."