Toronto Blue Jays Lyon made his major league debut halfway through the 2001 season, posting a five-win, four-loss record for the
Toronto Blue Jays, with a 4.29
ERA from 11 starts. He was the second youngest winning pitcher in Blue Jays' history after winning on debut (2–1 over
Baltimore). 2002, however, was a different story. Lyon started the season as a starter for the Jays, but lost three of his first four decisions of the season, including a career-high 7 earned runs against the
Yankees on April 10, and against the
Angels on May 3. Three weeks later, Lyon was kicked from the rotation, and placed in the
bullpen. He made his debut in this role at the
SkyDome, against
Boston, pitching 3 innings. In five games of relief, Lyon had no decisions against him with a 5.19 ERA.
Boston Red Sox During the postseason, the Red Sox claimed Lyon off waivers. Boston made Lyon a permanent reliever, and Lyon appeared in 49 games in 2003, converting 9 saves in 12 opportunities with 50 strikeouts in 59 innings pitched. Lyon missed the entire 2004 season due to injury, after having been traded along with
Casey Fossum, Michael Goss and
Jorge de la Rosa to
Arizona in exchange for
Curt Schilling.
Arizona Diamondbacks Lyon improved in 2005, converting 14 saves in 15 opportunities while pitching in 32 games and spending part of the season as the Diamondbacks'
closer, replacing the injured
José Valverde. However, he spent most of the second half on the disabled list. In 2006, Lyon had a very solid season, posting a 2–4 record and a 3.89
ERA in 68 appearances. In 2007, Lyon had probably his best season yet, with a 6–4 record, 2 saves, and the best ERA of his career, at a sparkling 2.68 in 73 games. Lyon found his niche as the Diamondbacks' primary
setup man, pitching in front of Valverde, as Arizona won the
NL West division title. For most of , Lyon served as the closer for the Diamondbacks following the offseason trade of Valverde to the Houston Astros. However, he lost the job to
Chad Qualls following second-half struggles.
Detroit Tigers On January 24, , the Detroit Tigers signed Lyon to a one-year contract. Lyon's Tiger season started off horrendously: Lyon compiled an ERA of 4.91 in April and a whopping 8.10 in May. From June on, Lyon redeemed himself somewhat by compiling a 1.56 ERA in 57 innings. Lyon was used as a set-up man for Tigers closer
Fernando Rodney. On November 10, 2009, Lyon filed for
free agency.
Houston Astros On December 12, 2009, Lyon signed with the Houston Astros to a 3-year deal, worth $15 million.
Toronto Blue Jays (second stint) On July 20, 2012, Lyon was traded to the Blue Jays, along with
J. A. Happ, and
David Carpenter, for
Francisco Cordero,
Ben Francisco,
Asher Wojciechowski,
David Rollins,
Joe Musgrove,
Carlos Pérez, and a
player to be named later (
Kevin Comer). He became a free agent following the season.
New York Mets On February 7, 2013, it was announced that the New York Mets and Lyon had reached an agreement on a one-year contract, which became official on February 8. Lyon was designated for assignment on July 5, 2013. On July 9, Lyon was released.
Boston Red Sox (second stint) On July 19, 2013, Lyon signed a minor league contract with the
Boston Red Sox. He was released on August 1.
Los Angeles Angels of Anaheim On February 10, 2014, Lyon signed a minor league contract with the
Los Angeles of Anaheim. On May 20, 2014, Lyon elected free agency after spending all season in Triple-A. ==Pitching style==