The Washington Nationals selected Pivetta in the fourth round of the 2013 Major League Baseball draft out of New Mexico Junior College. He signed with the Nationals for $364,300, and made his professional debut with the Gulf Coast Nationals of the Rookie Gulf Coast League. He ended the season with the Auburn Doubledays of the Class A- New York-Pennsylvania League. In nine games between the two teams, he was 1–1 with a 2.91 ERA. Pivetta spent 2014 with the Class A Hagerstown Suns, where he was a South Atlantic League mid-season All-Star, the June 23 SAL Pitcher of the Week, and where his 13 wins were third in the SAL and tied for first among all Washington minor leaguers. He finished the season with a 13–8 record, 4.22 ERA, and 1.37 WHIP in 26 games. Following the season, Baseball America named him the 10th-best prospect in the Nationals' minor league system. In 2015, Pivetta was 7-4 with a 2.29 ERA for the Class A-Advanced Potomac Nationals, and was a Carolina League All Star.
Philadelphia Phillies
2015-17
On July 28, 2015, the Nationals traded Pivetta to the Philadelphia Phillies for Jonathan Papelbon. In 2016, he was 11–6 with a 3.41 ERA and 111 strikeouts for the Double-A Reading Phillies, with whom Pivetta was an Eastern League mid-season All Star. He was also 1–2 with a 2.55 ERA and 27 strikeouts in 24.2 innings in five starts for the Triple-A Lehigh Valley IronPigs. The Phillies added him to their 40-man roster after the 2016 season. Pivetta played for Team Canada in the 2017 World Baseball Classic. In 2017, Pivetta went 5–0 with a 1.41 ERA for the IronPigs, and was Phillies Minor League Pitcher of the Week for the week ended April 16. Pivetta was promoted to the 25-man roster on April 30, making his debut the same day against the Los Angeles Dodgers. He was then 8–10 with a 6.02 ERA and 140 strikeouts in 133 innings for the Phillies. Among Major League rookies, he was 1st in strikeouts-per-nine-innings-pitched, and 3rd in strikeouts.
2018-present
In 2018, Pivetta was 7-14 with a 4.77 ERA, 5th in the National League with 10.32 strikeouts-per-9-innings-pitched, 8th in the NL in strikeouts and wild pitches, 9th in the NL in games started and strikeouts/walk, and led the major leagues in allowing opposing batters the highest batting average on balls in play. He struck out a career-high 13 batters on June 18 against St. Louis. His fastball was clocked as high as 98 miles per hour. In 2019, Pivetta struggled at the beginning of the season before being demoted to AAA. With Lehigh Valley he was 5-1 with a 3.07 ERA, as in 9 games and 41.0 innings he struck out 58 batters, and giving up 23 hits had the best hits/9 innings ratio in the league at 5.0. On July 19, it was announced he would be shifted to a relief role. In 2019 with the Phillies he was 4-6 with one save and a 5.38 ERA, as in 30 games he pitched 93.2 innings.
Pitching style
Pivetta throws a four-seam fastball, a curveball, a slider, and a changeup. He relies mostly on his fastball, which averages 96 miles per hour, and his two breaking balls. In 2017 and 2018, he threw his fastball 59 percent of the time, his 80 mph curve 19 percent of the time, and his 85 mph slider 15 percent of the time.
