Michigan State running back Kenneth Walker III (9) runs for a touchdown past Northwestern safety Brandon Joseph (16) during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Northwestern quarterback Hunter Johnson throws against Michigan State during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State quarterback Payton Thorne runs with the ball during the first half of the team's NCAA college football game against Northwestern in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State running back Kenneth Walker III, left, celebrates with running back Elijah Collins after scoring a touchdown against Northwestern during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State quarterback Payton Thorne throws a pass against Northwestern during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Northwestern wide receiver Bryce Kirtz, left, reaches in vain for a pass as Michigan State cornerback Kalon Gervin defends during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Northwestern coach Pat Fitzgerald stands along the sideline during the first half of the team's NCAA college football game against Michigan State in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State running back Kenneth Walker III., right, is tackled by Northwestern linebacker Khalid Jones during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Northwestern running back Andrew Clair (11) carries against Michigan State during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Northwestern defensive lineman Joe Spivak (1) holds a pole bearing a U.S. flag as he runs onto the field with teammates before an NCAA college football game against Michigan State in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State safety Xavier Henderson (3) celebrates with safety Michael Dowell (7) after Henderson tackled Northwestern wide receiver Stephon Robinson Jr. (5) during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State coach Mel Tucker, center, runs onto the field with the team before an NCAA college football game against Northwestern in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

A Michigan State fan cheers for team before an NCAA college football game against Northwestern in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State running back Kenneth Walker III, right, celebrates with wide receiver Jayden Reed after scoring his second touchdown during the first half of an NCAA college football game against Northwestern in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

Michigan State running back Kenneth Walker III (9) celebrates with running back Elijah Collins (24) after Walker scored a touchdown during the first half against Northwestern in an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. At right is quarterback Payton Thorne. (AP Photo/Nam Y. Huh)

Michigan State running back Kenneth Walker III runs past Northwestern defensive back Bryce Jackson on the way to a touchdown during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. (AP Photo/Nam Y. Huh)

FILE - Northwestern quarterback Hunter Johnson throws against Michigan State during the first half of an NCAA college football game in Evanston, Ill., Friday, Sept. 3, 2021. Onetime Clemson quarterback Johnson is returning to the Tigers for his final season of college football, in 2022. It's Clemson coach Dabo Swinney's first foray into the NCAA transfer portal. (AP Photo/Nam Y. Huh, File)