He played in Major League Baseball (MLB) for the Cincinnati Reds, San Francisco Giants, St. Louis Cardinals, Seattle Mariners, and Arizona Diamondbacks.

[1] Leake grew up as a Seattle Mariners fan and idolized Vladimir Guerrero and Nolan Ryan among others.

[2] He started playing baseball at age five by tagging along with his older brother everywhere, to the point that Ryan complained about Mike to his parents.

Chris and Sarah Leake convinced Ryan to put up with Mike and teach him how to act both on and off the field.

[1] His freshman and sophomore years, Leake attended Valley Center High School, where he started on the varsity baseball team.

[2] After graduating from high school, Leake attended Arizona State University, where he majored in management.

His 13 wins, the third most in Arizona State history by a freshman, tied him with his teammate, Josh Satow, for the Pac-10 lead.

Continuing where he left off at the end of his freshman year, Leake had an 11–3 record with a save and a 3.49 ERA in his 19 appearances, 16 of which were starts.

During his junior year, Leake went 16–1 with a 1.71 ERA, 142 innings pitched, and 162 strikeouts, limiting batters to a .193 average, the second lowest in the Pac-10.

He threw seven complete games, including back-to-back shutouts, and compiled 26 straight scoreless innings at one point.

[2] Leake was drafted out of high school in 2006 by the Oakland Athletics in the seventh round (218th overall), but chose instead to attend college.

[5] In 2010, Leake competed for the Reds' fifth starter spot and ultimately won a spot on the Reds' twenty-five man roster amid competition from veterans Mike Lincoln, Justin Lehr, and Micah Owings and young pitchers Travis Wood and Aroldis Chapman.

[7] Leake became the first player since Xavier Nady, when he was with the San Diego Padres in 2000, to go directly from the draft to the major leagues,[8] and is the first starting pitcher to accomplish the feat since left-hander Jim Abbott of the California Angels in 1989.

[11] With a career record of 4–0 at that point, he became the first Reds rookie starting pitcher to open 4–0 since Pat Zachry and Santo Alcalá did so in 1976.

[12] Leake became the first rookie pitcher in Reds' history to remain undefeated after his 10th start by throwing six innings of shutout ball on May 30, 2010, against the Houston Astros.

[12] Leake began to suffer from shoulder fatigue as the season progressed, and he was eventually put on the disabled list (DL).

Leake did throw a bullpen session late in the month, but was determined to be not ready for pitching in the post season and effectively "shut down" once again.

[citation needed] Entering spring training, Leake was considered the sixth man in the rotation, and faced starting the season in the minor leagues.

Leake was optioned to triple-A for the first time in his career on May 14 to make room for reliever José Arredondo to come off the DL.

[16] Leake was called back up on May 28 and started against the Braves, earning the win and pitching six innings of one-run ball.

[17] On May 21, 2012, Leake hit the first home run of his career, off Mike Minor of the Atlanta Braves in the fourth inning of a game at Great American Ball Park.

Leake was scratched from his second scheduled start with the Giants due to a strained hamstring[19] and was placed on the disabled list.

On August 30, 2017, the Cardinals traded Leake and international signing bonus space to the Seattle Mariners for Rayder Ascanio.

[27] In five starts with the Mariners, he finished strong with a 3–1 record with 2.53 ERA, 27 strikeouts, and 2 walks in 32 innings pitched.

[32] On July 19, against the Angels, Leake took a perfect game through eight innings until allowing a leadoff hit by Luis Rengifo.

[42] He had purchased an equal value of shirts earlier from Macy's, claimed he was trying to make an even exchange without talking to employees or going to customer service.

[43] Leake was charged with theft, a first-degree misdemeanor in Ohio that carried a maximum sentence of 180 days in jail if convicted.

[44] He pleaded guilty to a reduced charge of unauthorized use of property and entered a court-sponsored diversion program and was required to complete 30 hours of community service and counseling, upon which his case was dismissed.