The Washington Nationals selected Ray in the 12th round of the 2010 Major League Baseball draft. He signed with the Nationals, receiving a $799,000 signing bonus. Ray pitched in one game for the Vermont Lake Monsters in 2010, striking out two in one inning pitched. Pitching for the Hagerstown Suns in 2011, he went 2–3 with a 3.13 earned run average with 95 strikeouts in 89 innings pitched. Ray struggled pitching for the Potomac Nationals in 2012, going 4–12 with a 6.56 ERA. He returned to Potomac for the start of the 2013 season. After going 6–3 with a 3.11 ERA and 100 strikeouts in 84 innings, he was promoted to the Double-A Harrisburg Senators. He posted a 5–2 record with a 3.72 ERA at Harrisburg.
Detroit Tigers
On December 2, 2013, Ray was traded to the Detroit Tigers, along with Ian Krol and Steve Lombardozzi Jr., for Doug Fister. Ray started the 2014 season with the Triple-A Toledo Mud Hens. The Tigers announced he would be called up to the Major League team following an April 26 injury to starter Aníbal Sánchez. Ray made his Major League debut on May 6, 2014, earning his first big-league win in the Tigers' 11–4 victory over the Houston Astros. On August 12, he was recalled to replace an injured Aníbal Sánchez again. Ray pitched five innings, allowing four runs on six hits, while striking out five and walking two, in a 4–2 loss to the Pittsburgh Pirates.
Arizona Diamondbacks
On December 5, 2014, the Tigers traded Ray and Domingo Leyba to the Arizona Diamondbacks in a three-team trade that brought Shane Greene to the Detroit Tigers, and Didi Gregorius to the New York Yankees. He started the 2015 season at their AAA affiliate, the Reno Aces. He made his debut in a Diamondbacks uniform on May 6, being called up to face the Colorado Rockies in the second game of a doubleheader. Ray hit his first career home run on June 7, 2016, off of Chris Archer. Despite striking out 218 batters, Ray finished 8–15 with a 4.90 ERA in 174⅓ innings in 32 starts, giving up 24 home runs and recording just 10 quality starts in 32 total starts. In 2016 he led the major leagues in allowing opposing batters the highest batting average on balls in play. In his first month and a half of 2017, Ray pitched poorly, recording a 4.57 ERA in 8 starts. In his following 8 starts, however, he went 6–1 with a 1.81 ERA in 54⅔ innings, holding opponents to a.173 batting average. He pitched his first career complete game shutout on May 30 against the Pirates, striking out 10 while allowing just four hits. In his next two starts he struck out 11 and 12 batters respectively. In a five start stretch, Ray went 5–0 with an 0.24 ERA holding opponents to a.115 batting average and 48 strikeouts. On July 2, Ray was named to his first career All-Star game. At the time, he had an 8–4 record and a 3.06 ERA in 100 innings, with a.202 batting average against and 128 strikeouts. In a game against the St. Louis Cardinals on July 28, Ray was struck in the head on a line drive by Cardinal first basemanLuke Voit in the 2nd inning and carted off the field, but a CT scan later showed that he did not suffer any fracture and only needed a few stitches to his head. He was put on the 7-day concussion DL and did not return to the mound until August 24. On September 4, Ray struck out a career-high 14 batters while pitching 7 2/3 innings in a 13–0 victory against the Los Angeles Dodgers. Ray earned his 12th victory of the season, and this would propel the Diamondbacks to their 11th consecutive victory. He finished the season with 15–5 with 218 strikeouts and a 2.89 ERA over 162 innings in 28 starts. His 12.11 K/9 rate was the best in the National League and he held opponents to a.199 batting average. In 2017 he had the highest rate of bases on balls per 9 innings pitched in the majors, and led the majors in giving up the highest percentage of hard-hit balls. He also led major league pitchers in lowest contact percentage. Ray began the 2018 season as the Diamondbacks #2 starter. He was placed on the disabled list on April 30 with an oblique injury. He finished the season 6–2 with an ERA of 3.93 in 24 starts. In innings, he struck out 165 batters, and gave up 70 walks. Ray pitched a career high 33 starts in 2019 despite averaging less than 6 innings per start. He was 12-8 with a 4.34 ERA in innings, tying his career best innings pitched from 2016. He also struck out a career high 235 batters.
Pitch selection
Ray throws a fastball in the range, topping out at. His primary offspeed pitches are a slider that averages about and a curveball that he throws at about.
