BOSTON – When he left his office two weeks ago to celebrate Canada’s Thanksgiving, Alex Anthopoulos still felt “100 percent” certain John Farrell would manage the Blue Jays next season.

Farrell had other plans.

Upon returning to Toronto after the Oct. 8 holiday, the Jays’ general manager spoke to Farrell for the first time since the regular season ended – and since the Red Sox fired Manager Bobby Valentine.

Farrell told Anthopoulos that managing in Boston was his “dream job,” and that he would appreciate the Blue Jays freeing him from the final year of his contract if the Red Sox expressed interest in him.

“I explained to him that, at that time, we hadn’t gotten any phone call at all,” Anthopoulos said, “and that we couldn’t hold up our offseason and even go down that path if we hadn’t gotten a phone call.”

A few days later, Red Sox principal owner John Henry phoned Jays President Paul Beeston.

And away they went.

“As John explained it to me, this was a dream job for him,” Anthopoulos said. “It was a once-in-a-lifetime opportunity that he felt very strongly about. We would do what we could, but he also understood that we weren’t just going to send him there or give him away or let him out of his contract. That wouldn’t have made any sense for us.”

Negotiations on potential compensation began immediately. According to Anthopoulos and two major league sources, the talks existed mostly at the ownership level – between Henry, Red Sox President Larry Lucchino and Beeston – and centered around major league players who could make an immediate impact in the Jays’ lineup, not prospects.

The on-again, off-again discussions continued for nearly 10 days, during which time Red Sox GM Ben Cherington interviewed four managerial candidates: Dodgers third-base coach Tim Wallach, Yankees bench coach Tony Pena, Padres special assistant Brad Ausmus and Orioles third-base coach DeMarlo Hale.

But one industry source maintained the process wasn’t a charade, noting the Blue Jays didn’t grant permission for the Red Sox to speak with Farrell until Friday night.

Until then, and even in the hours before they reached agreement on a three-year contract with Farrell late Saturday night, the Red Sox weren’t sure they’d be able to pry their well-respected former pitching coach from Toronto. Compensation remained a sticking point into the weekend, with the Jays ultimately agreeing to take infielder Mike Aviles.

Likewise, Anthopoulos insisted the Jays were prepared to move forward with Farrell as their manager if a deal with the Red Sox couldn’t be reached.

“We were proceeding with interviews because we had no reason to believe the conversations (with the Blue Jays) were going to lead to permission,” one Red Sox source said.

Because major league rules prohibit a manager from being traded for a player, the Red Sox also received reliever David Carpenter, who is 1-5 with a 5.70 ERA and 60 strikeouts in 60 innings and 67 major league appearances. Anthopoulos said the Jays had planned to remove Carpenter from their 40-man roster anyway, making him a small sacrifice.

But Farrell was the Red Sox’s big prize, Plan A in their second managerial search in as many years. Ace lefty Jon Lester always has enjoyed a close relationship with Farrell, and even before the hiring became official Sunday, he tweeted, “Welcome back John!! Can’t wait to get back to work!!”

With the Blue Jays, Farrell produced underwhelming results: a 154-170 record, back-to-back fourth-place finishes and, recently, rumors of clubhouse discord. But unlike Valentine, or any of the other nine candidates who have interviewed with the Red Sox the past two years, Farrell has the support of both ownership and baseball operations.