Gabbard was called up from Triple-A Pawtucket to pitch on May 20,, against Atlanta in place of Josh Beckett. He had a good performance allowing 2 runs on 6 hits over 5 innings and got the win. He was then immediately optioned back to Pawtucket after the game. Gabbard started on June 26, 2007, against Seattle in place of Curt Schilling, who was placed on the disabled list. Gabbard had a sub-par performance, earning a no decision, and lasted only 3 innings allowing 4 runs on 6 hits while walking six and striking out two. Gabbard performed well in his third start of the season on July 2, 2007, allowing three runs on three hits while walking four and striking out five, earning the win. He tossed his first complete game shutout on July 16, 2007, against the Kansas City Royals in a 4-0 victory, allowing only 3 hits, 1 walk, and striking out 8. Gabbard was traded to the Texas Rangers on July 31, 2007, for relief pitcherÉric Gagné, the same day the Atlanta Braves traded his high school teammate Saltalamacchia to Texas. The Red Sox would go on to win the 2007 World Series, and Gabbard was awarded a World Series ring by the team. Gabbard made his Ranger debut on August 2, 2007, against the Cleveland Indians. He was pinned for the loss as the Indians won the game 5-0. Less than three weeks later, on August 22, Gabbard was the winning pitcher in a game where the Rangers outscored the Baltimore Orioles 30-3, the most runs scored in a game in the modern era.
2008
On May 8,, in a game against the Seattle Mariners, Gabbard was charged on the mound by Seattle's Richie Sexson. Sexson threw his batting helmet at Gabbard after Gabbard's head-high pitch towards Sexson. Sexson later stated he was frustrated and had a lot going on in his head, including his club's recent struggles. Sexson was suspended six games for the incident; a successful appeal lowered the suspension to five games.
2009
After the Rangers' 2009 spring training camp, Gabbard was sent outright to the Triple-A Oklahoma City RedHawks. On April 22, Darren O'Day made his Rangers debut, but was so new his jersey had yet to arrive, so was forced to borrow Gabbard's jersey. On April 23, the Red Sox re-acquired Gabbard from the Rangers for cash considerations. They assigned him to the Pawtucket Red Sox. As of July 27, Gabbard went on a rehab assignment in the Red Sox farm system, pitching for the single-A affiliate Lowell Spinners. As of July 24, 2010, the Boston Red Sox released Gabbard, making him a free agent. He retired in 2012.
Pitching style
Gabbard had the standard repertoire of fastball, curveball, and changeup, occasionally throwing a slider. Gabbard's fastball hit the high-80s, his changeup worked the best low and away on right-handed hitters, and his slow curveball was especially effective against lefties. Not a power strikeout pitcher, Gabbard was compared to Mark Buehrle and Kenny Rogers.