Kennedy was drafted by the
Tampa Bay Devil Rays in the eighth round (252nd overall) of the
Major League Baseball draft. He made his major league debut on June 6, with the Devil Rays.
Tampa Bay Devil Rays Kennedy made his Major League debut on June 6, 2001, becoming the first lefthander to start a game for the Devil Rays in 219 games. He finished 7–8 in 20 starts for the Devil Rays. In his second season, he pitched in 30 starts going 8-11 while throwing 5 complete games for the Devil Rays. In 2003, he was named the Opening Day starter for the Devil Rays after having an abysmal spring training. He made 22 straight starts before being relegated to the
bullpen after suffering an arm injury in . He had pitched in 72 consecutive starts for the Devil Rays before being moved to the bullpen. He recorded his first career save on September 10, 2003, against the Blue Jays, pitching three scoreless innings.
Colorado Rockies Traded to the
Colorado Rockies before the season, Kennedy became the first Rockies starter to have a sub 4.00
earned run average, setting a franchise record with a 3.66 ERA while going 9-7 for the Rockies. In 2005, Kennedy struggled as a starter for the Rockies, going 4–8 with a 7.04 ERA.
Oakland Athletics On June 5, 2005, the A's showed interest in Kennedy. On July 13 of that year, Kennedy, along with pitcher
Jay Witasick, was traded by the Rockies to the Oakland Athletics for
outfielder Eric Byrnes and
minor league infield prospect
Omar Quintanilla. Kennedy pitched in the bullpen for Oakland before being pressed into the starter role in September when
Rich Harden was injured. Kennedy went 1-5 as a starter for Oakland, and finished the year with a 4–5 record and a 4.70 ERA in the
American League. Kennedy pitched well in a middle relief role in Oakland's bullpen in 2006, with a record of 4-1 and a 2.31 ERA. Unfortunately, his role was diminished as he missed three months with shoulder and biceps injuries. Despite struggling in spring training with an ERA above 11.00, Kennedy was named the fifth starter for the Athletics at the start of the season. Through June 2 he compiled a 1–4 record with a 3.30 ERA in 62 innings. He was ineffective afterwards and was placed on waivers.
Arizona Diamondbacks Kennedy was claimed by the Arizona Diamondbacks on August 4 after being placed on waivers by the Athletics. He was
designated for assignment on August 15 after allowing 7 runs in 3 games and was released by the Diamondbacks.
Toronto Blue Jays He signed a minor league contract with the Toronto Blue Jays on August 28 and was called up to the major league team on September 2. He pitched in nine games, all in relief, for the Blue Jays in the final month of the season and went 1–0 with a 5.14 ERA. He became a free agent after the season. ==Scouting==