Wheeler transferred to the cavalry branch and commanded the 2nd Cavalry Brigade of the Left Wing in the Army of Mississippi from September to October. During the Kentucky Campaign, Wheeler aggressively maintained contact with the enemy. He began to suffer from poor relations with the Confederacy's arguably greatest cavalryman, Nathan Bedford Forrest, when Bragg reassigned most of Forrest's men to Wheeler, sending Forrest to Murfreesboro to recruit a new brigade. Wheeler fought at the Battle of Perryville in October and after the fight performed an excellent rearguard action protecting the army's withdrawal. He was promoted to brigadier general on October 30 and led the cavalry belonging to the Second Corps of the Army of Tennessee from November to December. During action at La Vergne, Tennessee, on November 27, Wheeler was wounded by an artillery shell that exploded near him.