Bumgarner, ranked the No. 6 top prospect in the Minors by MLB.com, was promoted by the Giants along with right-hander Tim Alderson and shortstop Brandon Crawford to Double-A Connecticut following their game with San Jose on Wednesday night.
Bumgarner, one of the Giants' first-round picks in the 2007 Draft, was promoted to San Jose this season after a breakout campaign with Class A Augusta in 2008. The 19-year-old southpaw was named Minor League Baseball's Most Spectacular Pitcher, the South Atlantic League's Most Outstanding Pitcher and MLB.com's Class A Starting Pitcher of the Year after finishing the season 15-3 and owning the lowest ERA in the Minors (1.46) in 24 starts. The former No. 10 overall pick struck out 164 in 141 1/3 innings.
He went 3-1 in five starts for San Jose and owned the third-lowest ERA in the California League (1.48).
Alderson's promotion is somewhat overdue -- a fellow first-round pick from 2007, Alderson was named MLB.com's Class A Advanced Starting Pitcher of the Year in 2008 after he went 13-4 with a 2.79 ERA in 26 outings for San Jose.
The 20-year-old Scottsdale, Ariz., native struck out 20 in 26 innings this season and was 1-1 with a 4.15 ERA in five appearances with the Giants before his promotion.
He allowed two runs over seven strong innings in his last start on May 3 for his first win.
Crawford, a UCLA product out of Mountain View, Calif., is batting .391 in his last 10 games and had reeled off four consecutive multi-hit efforts before his promotion Wednesday night. He's batting .371 with six homers and 17 RBIs through 25 games with San Jose and ranks second in hits (39) and fourth in average in the League.
Bumgarner and Alderson join a Defenders rotation that already boasts some talented arms, including 2008 SAL All-Star Daryl Maday (1-1, 2.17, 18 K) and 2007 Futures Game All-Star Henry Sosa (1-0, 2.35, 17 K).
Danny Wild is an editor for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.