Due to injuries to James McDonald and Wandy Rodríguez, the Pirates promoted Cole to the major leagues, to make his MLB debut on June 11, 2013.[28][29] During his debut, he struck out the first batter he faced, Gregor Blanco, on three pitches; the last one at 99 miles per hour (159 km/h). He also recorded his first career hit, a 2-run single with the bases loaded in his first career plate appearance. Cole pitched 6+1⁄3 innings being charged with two earned runs but got the win as the Pirates won over the San Francisco Giants, 8–2. Cole became the fourth pitcher since 1920 to drive in 2+ runs and earn the win in his Major League debut. Cole is the first Pirate to start his career with wins in his first four starts since Nick Maddox in 1907.[30] He was the fifth pitcher for any team to accomplish the feat in the past 40 years, joining Rich Gale of the 1978 Royals, Kaz Ishii of the 2002 Dodgers, Jered Weaver of the 2006 Angels and Scott Lewis of the 2008 Indians.[31]
Cole was voted the National League (NL) Rookie of the Month for September 2013. On the month, Cole had a 4–0 record and led all rookies with a 1.69 ERA and 39 strikeouts.[32] Cole had a 10–7 record and a 3.22 ERA in 19 starts for Pittsburgh in 2013. Cole started Game Two of the 2013 National League Division Series, going six innings allowing two hits, one earned run, and five strikeouts, and ultimately defeating the St. Louis Cardinals.[18] The Pirates chose Cole to start the deciding Game 5 over A. J. Burnett.[29] The Cardinals won the game, and the series.[33]
After focusing on his fastball during his rookie season, Cole entered 2014 spring training working on improving his curveball and slider.[34] Cole had been a durable pitcher in 2014 pitching 75+1⁄3 innings, but manager Clint Hurdle acknowledged on June 7 that Cole would miss at least one start with shoulder fatigue.[35] Cole was placed on the 15-day disabled list the next day,[36] and activated on June 28.[37]
On September 7, 2014, Cole hit his first career home run at Wrigley Field off of Chicago Cubs pitcher Blake Parker.[38] On September 23, Cole helped the Pirates clinch a second consecutive playoff berth by beating Alex Wood and the Atlanta Braves.[39]