Emperor Wu, who had been distancing Wei Qing and giving the younger Huo Qubing more attention and favour, hoped that Huo would engage the stronger Chanyu's tribe and preferentially assigned him the most elite troopers. The initial plan called for Huo Qubing to attack from Dingxiang (定襄, modern-day Qingshuihe County, Inner Mongolia) and engage the Chanyu, with Wei Qing supporting him in the east from Dai Commandery (代郡, modern-day, Yu County, Hebei) to engage the Left Worthy Prince (). However, a Xiongnu prisoner of war confessed that the Chanyu's main force was at the east side. Unaware that this was actually false information provided by the Xiongnu, Emperor Wu ordered the two columns to switch routes, with Wei Qing now setting off on the western side from Dingxiang, and Huo Qubing marching on the eastern side from the Dai Commandery.