Brendan Shanahan announced on Monday that Lou Lamoriello will not return as General Manager of the Toronto Maple Leafs next season.

Lamoriello signed a three-year contract a little less than three years ago which included a plan to transition into a senior advisory role for an additional four years as of 2018-19.

In July of 2015, Lamoriello arrived in Toronto in a surprising move to leave a reduced role in New Jersey in order to take on a daunting rebuilding project in the biggest market in hockey. Less than three years later, it could be fairly argued he was just what the doctor ordered for the franchise, by and large.

Arriving with the organization in total disrepair coming off of a circus of a season in 2014-15, Lamoriello put out the fires and oversaw the most controversy-free last place finish one could imagine in a market of this size and intensity, culminating in the drafting of Auston Matthews. Even if his style strikes some as a little old-school (army haircuts, no beards, restrictions on jersey numbers and media availability for rookies), it’s hard to argue that he hasn’t helped change the organizational culture for the better. He’s gotten away with things few others can in regards to burying contracts and bending rules. He’s also won all of his major trades.

The Leafs sold low in the Phil Kessel deal before Lamoriello showed up, which was likely always going to be the outcome to some degree, but the salary retention still strikes one as mind-boggling for a player of Kessel’s calibre. The two major deals under Lamoriello were the Phaneuf and Andersen deals – both, it would be fair to say, turned out to be home runs for very different reasons. The Leafs also netted strong returns when they sold at the deadline in the first few years of Lamoriello’s tenure – the Franson and Polak trades, among others – as it became clear quickly that Lamoriello wins in trade negotiations more often than not.

While the Matt Martin and Nikita Zaitsev deals merit some criticism, the contracts signed by Nazem Kadri, Morgan Rielly, Zach Hyman and Connor Brown suggest Lamoriello’s done a strong job overall of getting quality talent inked at team/cap friendly numbers.

The major concern upon Lamoriello’s arrival in Toronto was that it’d “Lou’s way or the highway,” based on his reputation throughout his storied career, but he seemed to step into the existing management structure well and understand, by his own words, that this wasn’t New Jersey (which was one of the first things he said when he arrived in Toronto). There was a lot of paranoia about his entry-level bonus philosophy, among other Lou-isms, and it was never actually an issue in Toronto.

The organization won a lottery in his time here and was blessed to welcome a franchise changer in Auston Matthews to the fold, but its growth from Day 1 of Lamoriello’s tenure to now has come in gargantuan leaps, and it has come much quicker than anyone was realistically expecting back in the summer of 2015 – from last place to sixth place in the NHL in the span of three seasons.

The main con to having Lamoriello stick around another year or more in the GM’s seat was that it was clear it would’ve risked the team losing Kyle Dubas, the team’s GM in waiting who has had other clubs knocking at the door, to say nothing the other assistant GM in Mark Hunter and what his ambitions might be. Shanahan has stuck the course here in regards to the three-year plan that involved Lamoriello running the team and serving in a mentorship role as the relatively inexperienced staff below him – Mark Hunter, Kyle Dubas — navigated NHL waters for the first time. Lamoriello will now move into a senior advisory capacity, as confirmed by the man himself, at least for the time being.

The transition to a new GM will take place during what is a big summer ahead for the organization, between some significant decisions on UFAs-to-be and the upcoming contract negotiations with all of Mitch Marner, William Nylander and Auston Matthews.

We’ll know more after Shanahan addresses the media at 1 p.m. EST.