Concussions could end Threet's ASU career

When Arizona State coach Dennis Erickson noted this month that quarterback Steven Threet probably would miss spring practices because he was still dealing with problems due to suffering three concussions during the 2010 season, it raised more than a few eyebrows.

Three concussions in 11 games? Still suffering symptoms nearly two and a half months later?

Now a source tells ESPN.com's Bruce Feldman that Threet's career is likely over.

"Doctors have told him a fifth concussion could be debilitating," the source told Feldman. "You don't want to be 35 years old and can't hold up a cup of coffee."

Update: Threet confirmed the decision to retire to the Arizona Republic.

Threet, a transfer from Michigan, will be a senior next year next fall. While he started 11 games in 2010, the general feeling around the program was that backup Brock Osweiler was the frontrunner to start in 2011, whether Threet was available or not, after Osweiler led the Sun Devils to wins in their final two games.

Osweiler replaced Threet early in the UCLA game and threw for 380 yards and four touchdowns in a 55-34 win. Osweiler then led the Sun Devils to a victory over rival Arizona.

Threet completed 62 percent of his passes for 2,534 yards with 18 touchdowns and 16 interceptions. Osweiler completed 57 percent of his throws for 797 yards with five touchdowns and no interceptions.

Still, Threet's loss is significant. For one, he might have staged a comeback this spring, and competition in itself likely would have been good for both Threet and Osweiler. Further, even if Threet didn't eclipse Osweiler, having an 11-game starter as a backup is a significant security blanket.

The Sun Devils QB situation is even more precarious because No. 3 Samson Szakacsy, who also had starting experience but suffered through recurrent arm problems throughout his career, retired this offseason to pursue other interests.

The good news is true freshman Michael Bercovici has already enrolled and will participate in spring practices, which may make him the frontrunner for the backup job. Also in the mix is redshirt freshman Taylor Kelly. Dual threat QB Michael Eubank arrives in the fall.