Chris Iannetta, he was traded to the Toronto Blue Jays for pitcher Brad Mills. Nine days later, Mathis signed a contract with the Blue Jays to avoid arbitration. He signed a one-year deal and was guaranteed to earn $1.5 million. Mathis made his first career pitching appearance in a game against the Texas Rangers on May 25. Pitching in the 8th inning, Mathis gave up a hit and walked a batter, but ended the inning without surrendering a run. He became the sixth position player for the Blue Jays to pitch in a game, and the first since Mike McCoy on June 11, 2011. He made a second pitching appearance exactly two months later, mopping up in a 16-0 loss against Oakland. In that game, Mathis gave up 3 hits and 2 runs (both earned) in 1 inning of work. On August 14, 2012, Mathis was signed to a two-year contract extension worth $3 million. It included a 2015 club option worth $1.5 million. Mathis was hitting .215 with six home runs over 147 plate appearances at the time of extension. Miami Marlins On November 19, 2012, Mathis was traded to the Miami Marlins along with Adeiny Hechavarria, Henderson Álvarez, Yunel Escobar, Jake Marisnick, Anthony DeSclafani, and Justin Nicolino, in exchange for Mark Buehrle, Josh Johnson, José Reyes, John Buck, and Emilio Bonifacio. Mathis was expected to serve as the back-up to Rob Brantly. In his first spring training game with the Marlins on February 23, 2013, Mathis broke his collarbone on a foul tip hit by Matt Holliday. He was the only catcher with major-league experience besides Brantly, and was expected to miss 6 weeks. Mathis made his season debut on May 16, going 0–4 with 2 strikeouts. On June 30, he hit a walk-off grand slam against Tyson Ross of the San Diego Padres to give Miami the win, 6–2. On November 1, 2014, the Marlins exercised their $1.5 million 2015 option on Mathis. On December 18, 2015, Mathis re-signed with the Marlins on a 1-year deal worth $1.5 million. He hit his third career grand slam (first since 2013) in a June 14, 2016 game against the San Diego Padres. Arizona Diamondbacks Mathis signed a two-year, $4 million deal with the Arizona Diamondbacks on December 5, 2016. During the 2017 season, he appeared in 60 games with the Diamondbacks, batting .215 with two home runs and 11