In 2009, McDonald was an Opening Day starter for the Reds. He played in the majors until May 21, when he was sent down to Louisville before being called back up on Aug. 25.
On Aug. 30, McDonald hit his first career home run, off of Clayton Kershaw, in a 3-2 Reds loss. He remained on the Reds roster for the rest of the season, hitting his second career home run on Sept. 17 off of Anibal Sanchez. He played 47 games for Cincinnati last season.