He played in Major League Baseball (MLB) for the Detroit Tigers, Boston Red Sox and New York Mets.

[1] His manager, Jim Leyland, chose to start him in the 2009 American League Central tie-breaker game over Nate Robertson, Eddie Bonine, and Armando Galarraga.

Although Porcello signed a letter of intent to attend the University of North Carolina, he later declined in order to pursue his professional career in Major League Baseball.

[3] His choice of sports agent Scott Boras to advise him may have scared away some teams, knocking him down to the 27th spot even though he was ranked No.

Porcello played the entire 2008 season with the Lakeland Flying Tigers of the Class A-Advanced Florida State League.

[12] On April 1, Dombrowski confirmed that Porcello would make the 2009 opening day roster after posting a 2.63 ERA in five Grapefruit League games.

[13]On April 9, Porcello made his Major League debut against Toronto, opposite Blue Jays rookie pitcher Ricky Romero.

Youkilis charged the mound, threw his helmet right in front of Porcello, and tackled him to the ground as both benches cleared.

On November 16, it was announced that Porcello finished third in the voting for American League Rookie of the Year, behind Andrew Bailey of the Oakland Athletics and Elvis Andrus of the Texas Rangers.

[21] In his first start back with the team, Porcello pitched very well, continuing the trend of struggling starters in the Tiger rotation finding success upon returning from the AAA Toledo Mud Hens.

Porcello entered Spring Training competing for a job in the Tigers starting rotation, battling with teammates Phil Coke, Jacob Turner, and Brad Penny for a spot.

On January 6, 2012, Porcello opted out of an option for 2012 included in his four-year contract, becoming arbitration eligible and under team control through 2015.

On September 10, Porcello pitched his first career complete game in his 147th major league start, resulting in a 9–1 win over the Chicago White Sox.

On January 17, 2014, Porcello and the Tigers avoided arbitration for the third straight season by agreeing to a one-year deal worth $8.5 million.

[31] In a more recent distinction, he became the first Major League pitcher to throw a no-strikeout shutout since Derek Lowe did it for the Indians on May 15, 2012.

[32] On August 20, Porcello pitched his third shutout of the season in a 6–0 win over the Tampa Bay Rays, giving up three hits, striking out four and walking none.

[33] On August 26, Rick defeated the New York Yankees 5–2 for his 15th victory of the season, establishing a new career high in wins.

On December 11, 2014, the Tigers traded Porcello to the Boston Red Sox in exchange for Yoenis Céspedes, Alex Wilson, and Gabe Speier.

[36] On April 6, 2015, Porcello and the Red Sox agreed on a 4-year contract extension worth $82.5 million, including a $500,000 signing bonus.

[37][38] On August 2, 2015, Porcello was placed on the Disabled List (retroactive to July 30) for the first time in his career, with the Red Sox stating he was suffering from triceps soreness and inflammation.

At the time, Rick was mired in his worst season, statistically, having posted a 5–11 record and a 5.81 ERA prior to the injury.

[40] In his next start, September 1 against the New York Yankees, Porcello struck out a career-high 13 batters in 8 innings, but lost a 3-1 decision.

Porcello rebounded from a bad season by leading the Red Sox back to the playoffs on the way to winning the Cy Young Award.

On September 9, 2016, Porcello became the first pitcher to reach 20 wins for the season, as the Red Sox defeated the Toronto Blue Jays, 13–3.

He also allowed 32 walks over the entire season, leading the major leagues with a 5.91 strikeout-to-walk ratio, and threw three complete games.

[43] On November 7, Porcello was announced by the Baseball Writers' Association of America (BBWAA) as a finalist for the 2016 American League Cy Young Award, along with Verlander and Corey Kluber.

On November 16, Porcello won the 2016 American League Cy Young Award in unique fashion.

Porcello became the fourth Red Sox pitcher to win the award, joining Jim Lonborg, Roger Clemens, and Pedro Martínez.

For the season, he made 32 appearances (all starts) compiling a 14–12 record with 143 strikeouts in 174+1⁄3 innings with a 5.52 ERA, the highest in the majors among qualified starters.