But on Monday, the Gold Glove Award-winning pitcher was traded to the Blue Jays as part of a 12-player deal.
Per team policy, the Marlins do not include no-trade clauses. But Buehrle claims he was given verbal assurances that he wouldn't be moved.
On Wednesday afternoon, Buehrle and his agent, Jeff Berry, co-head of CAA Baseball, issued a statement regarding the trade.
"In an offseason of change and uncertainty, the overriding factor in Mark's signing with Miami was Ozzie Guillen and the level of comfort his presence provided Mark and his family," Berry said. "While the Marlins were the highest bidder, baseball had already made Mark a wealthy man, so money was far from the most important factor in his decision.
"Throughout the recruiting process, the Marlins made repeated assurances about their long-term commitment to Mark and his family and their long-term commitment to building a winning tradition of Marlins baseball in the new stadium. This was demonstrated by their already completed signings of Ozzie, Heath Bell and Jose Reyes."
Buehrle on Monday was part of the largest transaction in Marlins history. The lefty was sent to Toronto along with Josh Johnson, Reyes, Emilio Bonifacio and John Buck.
Three weeks after the season ended, the Marlins dismissed Guillen as manager, replacing him with Mike Redmond, and they changed direction after finishing last in the National League East with a 69-93 record.
"At the same time, given the Marlins' history, we were all certainly aware of and voiced concern about the lack of no-trade protection," Berry said. "This is unquestionably a business, and signing with the Marlins was a calculated risk. Mark held up his end of the bargain; unfortunately, the same can't be said of the Marlins.
"That said, Mark is a consummate professional and is looking forward to joining his new teammates in Toronto."
After the trade was announced on Monday, Marlins president of baseball operations Larry Beinfest was asked about verbal assurances to Buehrle and Reyes.
Beinfest said he was unaware of them, and noted that typically, anything dealing with no-trade protection would be in writing.
"Speaking for myself, I am not aware of any assurances," Beinfest said. "I will tell you, if they came from me, they'd be in writing in a no-trade clause."
In his lone season with the Marlins, Buehrle was 13-13 with a 3.74 ERA. He made 31 starts and logged 202 1/3 innings.
Buehrle was awarded the Gold Glove Award as the best fielding pitcher in the National League.
"I'm upset with how things turned out in Miami," Buehrle said in a statement. "Just like the fans in South Florida, I was lied to on multiple occasions. But I'm putting it behind me and looking forward to moving on with my career."