In the trickling last days of the coaching carousel, a big move is reportedly being made at the assistant level.

Louisville defensive coordinator Todd Grantham has decided to take the same job at Mississippi State, the Bulldogs announced Wednesday. According to Pete Thamel of Sports Illustrated, who first reported the news, Grantham is taking a "multi-year" deal to replace Peter Sirmon, who will not return in 2017.

But as it so happens, Sirmon is reportedly headed to Louisville to replace Grantham, according to Football Scoop.

Or, is it Grantham replacing Sirmon? Football Scoop reports "the arrangement has been in the works for some time."

Either way, there's a literal coaching swap happening here.

Louisville has not confirmed the move on its end, though Mississippi State has already announced Grantham's hire.

"Todd has proven to be one of the best defensive coordinators in the country this decade," coach Dan Mullen said. "He understands what it takes to build a physical and aggressive defense at the highest of levels. We are excited to welcome he and his family to Starkville."

Added Grantham: "When the opportunity to be part of Dan Mullen's staff presented itself it was something my family and I became very excited abou. Coach Mullen has built a winning program in the most challenging conference in the country. Along with our staff, I look forward to re-establishing the Bulldog defense as one of the top defenses in the country and making the fans of Mississippi State proud."

Grantham is known for his aggressive style that puts an emphasis on limiting the run and creating takeaways. Louisville finished as a top-15 run defense in Grantham's three seasons, finishing in the top 10 in each of the past two campagins. The Cardinals have also been a top-25 defense in forcing takeaways during Grantham's stint with the program.

Prior to joining Bobby Petrino's staff, Grantham was the defensive coordinator at Georgia under former coach Mark Richt. He also has a long history at the NFL level as a defensive line coach and coordinator. He was the fifth-highest paid coordinator in college football last season, earning $1.3 million from Louisville.

In 2016, Mississippi State finished 13th in the SEC in scoring defense and dead last in passing defense.