Saying he will always remain a Toronto Blue Jays fan at heart, Alex Anthopoulos did not offer specifics Thursday when asked why he will not return as general manager of the team he built into a playoff contender, saying only "this was the right fit for me going forward."

Earlier in the day, news broke that Anthopoulos, 38, had rejected a contract extension with the team, leaving fans frustrated at news that the architect of the team's recent playoff run is now on his way out.

The Montreal native expressed thanks to the team in a telephone news conference held hours after the news broke.

"I just felt this was the right move for me at this time," he said. "I love the Blue Jays. By no means is this an easy decision, but it's one that I needed to make."

He said the team made every effort to bring him back. "This decision is solely mine," he said. "I own this decision. This is on me 100 per cent."

The development comes less than a week after the team enthralled baseball fans Canada-wide with its first playoff appearance in 22 years.

Anthopoulos was named baseball's executive of the year by the Sporting News on Thursday afternoon, after his departure from the Blue Jays had been announced.

In a news release issued a few hours after the news broke, the Blue Jays thanked Anthopoulos for "a job extremely well done."

The news comes ahead of the arrival of new team president and CEO Mark Shapiro, who is taking over from Paul Beeston.

Mike Wilner, who covers the Blue Jays for the Fan 590 radio station, said the team has made a "terrible move" in allowing the man behind their recent success to leave.

"It's a huge mistake on the Blue Jays part," said Wilner in an interview on CBC News Network shortly after the story broke. "[Anthopoulos] had a fantastic year, he might have had the best trade deadline ever."

The Blue Jays weren't considered a playoff contender at the mid-point of the Major League Baseball season. Then Anthopoulos made a handful of high-profile acquisitions at the trade deadline, including star pitcher David Price, shortstop Troy Tulowitzki and outfielder Ben Revere. Those moves catapulted the team to the American League East title.

The Jays beat the Texas Rangers in the American League Division Series before falling to the Royals in the league Championship Series.

There are reports the split may have happened over speculation about which man -— Shapiro or Anthopoulos — would have final say on player decisions. Some team presidents give their GMs a free hand in this area, others require sign-off from the president.

When asked whether a conflict about responsibility for player decisions with the incoming team was what made him decide to leave, Anthopoulos didn't answer the question directly.

"I don't think specifics … need to be discussed," he said. "I want to keep that private."

Anthopoulos said he is not leaving the Blue Jays for another baseball job.

"I have no job lined up," he said. "My focus was on the Toronto Blue Jays. What happens after that, I have no idea."

He also said the decision to leave was not money related, saying team owner Rogers Communications was "more than generous" during contract talks.

Fans not happy

Anthopoulos's departure raises questions about the future of a Blue Jays team whose return to the playoffs renewed excitement among Canadian baseball fans after years of losing. Fans packed Toronto's Rogers Centre and were glued to their television sets throughout the team's run. Moments from the playoffs — including Jose Bautista's bat flip and the heart-stopping (and heartbreaking) loss to the Royals — had many fans feeling confident the team would return to contention next year.

Now, with the architect of the team's recent success now heading out the door, fans expressed their frustration on Twitter. Much of that frustration was directed at Rogers.

The <a href="https://twitter.com/BlueJays">@BlueJays</a> are our team. Not <a href="https://twitter.com/Rogers">@rogers</a> not Shapiro. We the fans do not want <a href="https://twitter.com/hashtag/shapiro?src=hash">#shapiro</a> here. Bring back <a href="https://twitter.com/hashtag/AA?src=hash">#AA</a>. <a href="https://twitter.com/hashtag/cometogether?src=hash">#cometogether</a> my butt <a href="https://twitter.com/hashtag/boycott?src=hash">#boycott</a> —@halkiasmma

Toronto Mayor John Tory, whose resumé includes stints in executive positions at Rogers, said he was not happy to hear that Anthopoulos is leaving.

"He'll be sadly missed," said Tory. "He was somebody who engineered a team that put us into a very exciting position this fall."

The Blue Jays are also facing a number of key roster decisions this off-season, with pitchers Price and Marco Estrada's contracts expiring at the end of this season.