The high-fiving canine is a furry fixture at Huskies games along with his owner, Tom Bonnevier. The school's athletics director, Sean Frazier, says in a statement that Diesel "has become the face of Huskie football."
The university says 10-year-old Diesel will be honored during Tuesday night's game against Western Michigan. Once he becomes the school's "mascot emeritus," he'll be replaced by a husky named Mission. The new mascot is nearly 2-years-old.
The 18th-ranked team remains unbeaten this season and is hoping for a second consecutive BCS bid.
Mission is a Siberian husky donated to the university by John and Cassandra McKearn, the school's website said. His handlers will be members of the NIU ROTC program, and he has already been given the rank of colonel within the ROTC Battalion, an NIU news release said.
"I want to thank the McKearns for providing us with a worthy successor to Diesel, and Master Sgt. Rufus Beamon and the entire ROTC program for taking on the responsibility as Mission's handlers," Frazier said. "We look forward to enjoying hundreds of Huskie victories with Mission on our sidelines."
The Associated Press contributed to this report.