Middleton accepted a football scholarship from Indiana University with the plan of being the eventual successor at running back to Anthony Thompson. A chronic injury to his right ankle that he suffered in the Ohio All-Star game, forced the team to redshirt him in his first season. As a freshman, because of his size and athletic ability, the coaching staff wanted to find a way to get him on the field and converted him into a cornerback, although his body type was considered heavy for the position. As the starter at left cornerback he made 59 tackles, 5 tackles for loss, 2 sacks, one interception and one pass defensed. As a sophomore, he experienced a muscle spasm in the walls of his heart and missed 2 games. He finished the season with a career-high 65 tackles, 6 tackles for loss, 4 passes defensed and one interception. In the season opener he returned an interception 22-yards for a touchdown against the University of Kentucky. He had a career-high 15 tackles against Michigan State University. He also added 8 kickoffs returns for 169 yards. As a junior, he had 63 tackles, 4 tackles for loss and 7 passes defensed. In his last year, he was diagnosed with mononucleosis, which forced him to miss the first 2 games. He still was able to post 58 tackles, 3 tackles for loss, 3 passes defensed and one forced fumble. He put together a string of double-digit tackle performances over the final three games of the season. He also practiced track and field as a senior. He was a four-year starter, making 42 starts in 46 games, 245 tackles, 3 sacks, 15 passes defensed, 2 interceptions and one forced fumble.
Middleton was selected by the Dallas Cowboys in the third round of the 1993NFL Draft to play safety. He was released before the season started on August 23.
On December 1993, he was added to the Miami Dolphins practice squad. He was signed for the 1994 training camp, but was released before the season started on April 25.
On July 10, 1996, he signed with the Orlando Predators of the Arena Football League to play wide receiver/defensive back. On May 27, 1997, he was traded to the New York CityHawks along with the rights for John Bock in exchange for Curtis Cotton.
In March 2000, he signed to play for the Augusta Stallions at fullback/linebacker in the inaugural AF2 season. On May 12, 2000, he was placed on the injured reserve list after tearing a ligament in his ankle.
