In his one season in Ann Arbor, Richard pitched 21 games, mostly as a reliever and compiled a 0–1 record with a 2.43 ERA, a 1.20 WHIP, and 27 K's in 33.1 IP, good for a 7.29 K/9 innings ratio.

[3] He made his professional debut with the Rookie-level Great Falls White Sox and also played for the Single-A Kannapolis Intimidators in 2005, going 2–2 with a 3.33 ERA in 13 games (11 starts).

[4] In 2006, he played for Kannapolis and the High-A Winston-Salem Warthogs, posting a 7–9 record and 3.85 ERA in 22 games (21 starts) between the two teams.

[4] In 2008, he played with the Double-A Birmingham Barons and Triple-A Charlotte Knights, and posted a 12–6 record and 2.89 ERA in 20 starts for the two affiliates.

[4] On July 23, 2008, Richard made his major league debut, allowing five runs (four earned) on seven hits in four innings pitched against the Texas Rangers.

On July 31, 2009, Richard was traded along with Aaron Poreda, Adam Russell and Dexter Carter to the San Diego Padres for 2007 Cy Young Award-winner Jake Peavy.

[7][8]Richard made his first start for the Padres on August 1, 2009, recording no decision in 52⁄3 innings at home against the Milwaukee Brewers.

[6] On September 21, 2010, Richard threw his first career shutout, giving up eight hits, two walks, and recording six strikeouts in a win against the Los Angeles Dodgers along with a golden sombrero at the plate, striking out four times.

[6] A left shoulder strain forced Richard to the disabled list in July and later required arthroscopic surgery, ending his season.

[12] Richard opened 2013 as the Padres number two starter, but had a rough beginning to the season, posting an 8.54 ERA in his first six starts.

On June 1, Richard pitched two innings in relief to earn his first win of the season in a 17-inning affair against the Blue Jays that the Padres won 4–3.

[4] On December 3, 2014, Richard signed a minor league deal with an invite to spring training with the Pittsburgh Pirates.

[19] Through nine starts for the Triple-A Indianapolis Indians, Richard had a 2.09 ERA in 50 innings of work, also pitching in one game for the High-A Bradenton Marauders.

[22] After electing for free agency, Richard re-signed with the club two days later to take a bullpen role when reliever Rafael Soriano developed a sore shoulder.

[29] After two appearances out of the bullpen, Richard joined the San Diego rotation and made nine starts over the remainder of the season.

[30] Richard was a fixture in the San Diego rotation in 2017, leading the team with 1971⁄3 innings over his 32 starts, including two complete games.

He allowed a league-high 240 hits with a 4.79 ERA, but was third in the Major Leagues with a 59.2% ground ball rate and posted a personal best 6.9 strikeouts per 9 innings.

[31] In 2017, he led the major leagues in allowing opposing batters the highest batting average on balls in play (.351).

[36] On December 30, 2018, Richard was traded to the Toronto Blue Jays for minor league outfielder Connor Panas.

[47] From 2009 to 2013, Richard's pitching repertoire consisted of a four-seam and a two-seam fastball (90–95 MPH), a changeup, a slider, and an occasional curveball.