Ohio State is replacing defensive coordinator Greg Schiano with a pair of new defensive coaches, one of them a longtime assistant from rival Michigan.

Former Wolverines defensive line coach Greg Mattison and former San Francisco 49ers assistant Jeff Hafley will join the Buckeyes as co-defensive coordinators, the school announced Monday afternoon. The significant shake-up to the coaching staff comes at the conclusion of Ryan Day's first week as the program's new head coach.

"I love the idea of having two coordinators on defense," Day said in a news release. "I like having a diversity of opinion, but even more I like the expertise and experience that Jeff has in the secondary coupled with the expertise that Greg brings to the front seven."

Day and Hafley worked together for one season on the 49ers' staff under Chip Kelly in 2016. Day also worked with Mattison on Urban Meyer's staff at Florida in 2005.

Mattison comes to Columbus after spending the past eight seasons at Michigan. He spent 13 total seasons, including a stint in the early 1990s, coaching the Buckeyes' chief rival. Sources told ESPN's Tom VanHaaren that Michigan offered Mattison a two-year contract extension and a pay increase before his departure.

Schiano leaves the program after three seasons as defensive coordinator under Meyer. Schiano had been working under a one-year deal worth $1.5 million; a source told ESPN's Adam Rittenberg that the contract expires on Jan. 31.

In other moves on the defensive coaching staff, Day promoted defensive line coach Larry Johnson to associate head coach and Michigan linebackers coach Al Washington left the school with Mattison to join the Buckeyes.

Ohio State compiled a 13-1 record in the 2018 season but ranked 71st nationally on defense. The Buckeyes gave up 49 points in a trouncing by Purdue and 51 in a one-point win over Maryland.

Schiano, a former head coach at Rutgers and then for the Tampa Bay Buccaneers in 2012 and 2013, was nearly hired as the University of Tennessee's head coach in 2017. He had a verbal deal, but it fell apart after fans protested the hire, partly because of an allegation in grand jury testimony that he was aware of an incident at Penn State involving convicted sexual abuser Jerry Sandusky.

Schiano has denied any knowledge of such an incident.

Day said Monday evening via Twitter that Schiano will look for new job options in the NFL.

"I want to thank coach Greg Schiano for the example he set every day, for the players and the members of this coaching staff, of what it means to be selfless, committed and dedicated," Day said. "Our players saw these attributes in Greg and they learned from his example. I, personally, also want to thank Greg for wisdom and thoughtful guidance during my time as acting head coach this season. I wish him the best as he pursues options in the NFL."