Kancey, a junior, alluded to a health issue in an Instagram post as the main reason behind the decision.
"Thanks to the best trainers in the country at Pitt," Kancey said. "I know they will help me get back to 100% soon."
Kancey collected 7½ sacks and 14½ tackles for a loss in 11 games for the Panthers (8-4). He is the first Pitt player to win the conference's highest defensive honor since Aaron Donald in 2013.
The 6-foot-1, 280-pound player has been coy about his intentions next year, though the Miami native likely has worked himself up NFL draft boards over the past three months.
Kancey did say he plans to help teammates prepared for whatever bowl they might be headed to.
Pitt did not defend the ACC title it won a year ago but finished strong, winning four straight to end the season to come in second to North Carolina in the ACC's Coastal Division.