On August 15, 2011, Bundy signed a major league contract with the Baltimore Orioles, which added him to their 40-man roster.
Bundy made his professional debut on April 6, 2012 with the Single-A Delmarva Shorebirds pitching against the Asheville Tourists. He allowed no hits over three innings while striking out six batters. His fastball was reported to reach 97–98 mph in the game. In 30 innings pitched with Delmarva, Bundy maintained an ERA of 0.00 with 40 strikeouts, two walks and two unearned runs. Hitters went 5 for 94 against him.
Bundy had not pitched since spring training, and on June 27, 2013, he underwent Tommy John surgery. He was expected to miss at least 12 months. As of January 2014, Bundy had circled June 28, 2014—one year and one day after his Tommy John surgery—as the target date for his return.
Bundy is one of the most physically gifted pitchers in professional baseball, and he is remarkably advanced for his age. He throws four-seam, two-seam and cut-fastballs as well as two off-speed pitches—a curveball and a changeup. He throws his fastball with well-above average velocity and movement. His four-seamer sits in the 94–96 mph range and touches 100. Bundy's second-best pitch is his 88–94 mph cutter. He uses his cutter primarily against left-handed batters to overpower them on the inner-half of the strikezone. He also throws a curveball at 75–82 mph that rates as one of the best in the Orioles system, as well as a solid changeup.
Beyond his extraordinary fastball velocity and late-breaking curveball, Bundy also has impressive command—especially for a young power pitcher. His balanced, fluid delivery and repeatable mechanics allow him to throw strikes consistently and he is able to spot his fastball around the strike zone with precision.