Cook told reporters Thursday night that unless "things go really well," he will be back to lead the Spartans' offense as a senior. Cook, a native of Hinckley, Ohio, is 13-0 in Big Ten games as Michigan State's starter and last fall led the Spartans to a league championship and a Rose Bowl title.
"I've always talked about it with my parents and stuff, and you want to use up your eligibility," Cook said after Thursday's practice. "Michigan State's a great place, and I've had a lot of fun here and I had a lot of great relationships. You never want to kiss stuff goodbye.
"I looked at it the same way as graduating high school early to come to school. You only have one prom, you only go to high school once, you only go to college once is how I look at it."
The 6-foot-4, 218-pound Cook has completed 120 of 198 passes for 1,868 yards with 17 touchdowns and six interceptions this season. He has six 200-yard passing performances and 14 for his career, and last week he became the seventh Michigan State quarterback to record 40 career touchdown strikes.
ESPN NFL draft Insider Mel Kiper Jr. had ranked Cook as the fifth-best quarterback in his latest positional rankings.
Cook left the door open to a possible departure if he's projected as a high first-round draft pick but added, "I don't think that's gonna happen."