Yusmeiro Petit participant of 2009 Major League Baseball season
Arizona Diamondbacks (2007–2009)
Petit was traded to the Arizona Diamondbacks on March 26, 2007, for Jorge Julio. He picked up his first win for the Triple-A Tucson Sidewinders on April 15 against the Colorado Springs Sky Sox, tossing six innings, allowing two earned runs off six hits with five strikeouts. He was recalled on April 22 and made his Diamondbacks debut that night against the San Francisco Giants, allowing two runs over seven innings in the loss. He earned wins in five of his next six starts, going 5–0 with a 2.21 ERA. He earned his first win for the Diamondbacks on July 3 against the St. Louis Cardinals, allowing one run over 51⁄3 innings.
Going into the 2009 season, Petit was the likely candidate for the fifth starter role in the pitching rotation or a long-relief role, out of the bullpen. He started the season in the major leagues for the first time in his career and posted a 0–1 mark with a 4.70 ERA in six relief appearances before being optioned to Tucson on April 27. He made 11 starts for the Sidewinders, going 3–3 with a 4.80 ERA. Petit was recalled on June 27 and remained in the Majors for the remainder of the season. He made his first start of the season for the D-backs on July 2 and earned a no-decision in a 4–3 loss against the Milwaukee Brewers after allowing only one run on two hits with four strikeouts in six innings. He held opposing batters to a .216 batting average for the season, including a .213 average as a starter. In 2009, Petit was mainly a spot starter for the Diamondbacks rotation and went 3–5 with a 4.31 ERA in 19 games, of which eight were starts.
On August 4, 2009, Petit took a no-hitter into the eighth inning against the Pittsburgh Pirates before it was broken up in the eighth with a single by Ronny Cedeño. It was the only hit he allowed in eight innings. He finished the season 3–10 with a 5.82 ERA in 23 games, of which 17 were starts.