The dead man's identity was not confirmed, state police Lt. Brian Cole said. He said the body was in a green GMC Sierra in the parking lot in Saginaw County's Saginaw Township.
"One of our troopers was patrolling the parking lot, observed a vehicle which appeared to match the description of the vehicle that the missing player was last seen driving," Cole said. "He observed a deceased male inside the vehicle."
A state police crime lab was called to the scene, he said.
"We've got to confirm the identification. It's going to take some time," Cole said.
Terry Trafford reportedly was last seen about 9:30 a.m. on March 3 at the Dow Event Center, the home arena for the Saginaw Spirit. The team reported on its website that Trafford might be driving a 1995 Green Chevy Sierra pickup.
Cole told The Associated Press earlier that the 20-year-old Toronto native was considered a "voluntary missing person."
Trafford has been with the Ontario Hockey League team for several seasons. His name was on the team's roster Tuesday, but Saginaw Spirit President and General Manager Craig Goslin earlier told The Saginaw News that the center was sent home "for a violation of rules."
Trafford wasn't permanently cut from the team but would "have to change his behavior and make some adjustments," Goslin said.
He spent four seasons with the Spirit, with 29 goals and 49 assists. He had eight goals and 24 assists this season.
Skye Cieszlak told the newspaper that she and Trafford have dated since 2010 and that he "was devastated" after the team sent him home "for partying on a road trip."
Cieszlak said Trafford sent her a text message Sunday that said, "his life was over and that he didn't want to do it anymore."