"Just about any (Marlins) player making money is going to Toronto," a source told ESPN.
Toronto is still without a manager after the Boston Red Sox hired John Farrell.
"It's a good day to be bluejay!" a tweet from Toronto's Jose Bautista read.
While Bautista was elated with the proposed trade, Marlins outfielder Giancarlo Stanton voiced his frustration via Twitter.
"Alright, I'm pissed off!!! Plain & Simple," Stanton tweeted.
Johnson, who has spent his entire career with the Marlins told the Palm Beach Post that he's "in shock, but really excited to start a new chapter in my life."
Major League Baseball will have to examine the amount of money and contracts changing hands before signing off on the deal.
The Blue Jays are sending shortstop Yunel Escobar, right-hander Henderson Alvarez, catcher Jeff Mathis and prospects Jake Marisnick (OF), Adeiny Hechavarria (SS), Justin Nicolino (LHP) and Anthony DeSclafani (RHP) to the Marlins, sources told ESPN.
Baseball America, in rankings released last week, have Marisnick as Toronto's No. 2 prospect, Nicolino as No. 5 and Hechevarria as No. 8.
Reyes (six years, $106 million) and Buehrle (four years, $58 million) just signed long-term deals with the Marlins last offseason. Buck has one year remaining at $6 million, Johnson has one year at $13.75 million and Bonifacio is eligible for arbitration after making $2.2 million last year.
In addition to adding Reyes and Buehrle, the Marlins also splurged last offseason on manager Ozzie Guillen and closer Heath Bell while making failed overtures to free agents Albert Pujols and C.J. Wilson.
Since the start of the 2012 season, Miami has fired Guillen and dealt Bell (Diamondbacks), infielder Hanley Ramirez (Dodgers), starting pitcher Anibal Sanchez (Tigers) and second baseman Omar Infante (Tigers). The Marlins also acquired first baseman Carlos Lee in a trade.
The blockbuster trade that is brewing, perhaps, should not come as a surprise, however.
"We've kind of lost our Marlins way," president of baseball operations Larry Beinfest said less than two weeks ago. "The real Marlins way was we always outperformed our challenges. Whatever our challenges were, whether it was playing in a football stadium or weather or a lack of fans, or lack of revenue for that matter, we always found a way to outperform our challenges."
In 20 years of existence, the Marlins have only twice made the postseason, but won the World Series each time. As wild-card teams, the then Florida Marlins won the 1997 and 2003 World Series.
While the team had hopes of at least a playoff appearance instead of a last-place finish in 2012, Buehrle and Reyes played up to expectations. Buehrle went 13-13 with a 3.74 ERA and topped 200 innings for the 12th year in a row and won a Gold Glove. Reyes hit .287 with 40 steals in 160 games.
Johnson, who led the NL in ERA in 2010, went 8-14 this year with a 3.81 ERA. He was limited to nine starts in 2011 because of right shoulder inflammation.
Information from ESPN The Magazine's Buster Olney and The Associated Press was used in this report.