CORVALLIS, ORE. ? Mike Riley was introduced Thursday for the second time as Oregon State’s football coach — four years after he left the Beavers for the NFL.

“I guess the world really is round,” Riley said a day after accepting a seven-year deal to replace Dennis Erickson, who left to coach the San Francisco 49ers.

The 49-year-old Riley coached the Beavers in 1997-98 before bolting to become head coach of the San Diego Chargers. Most recently he was defensive backs coach of the New Orleans Saints.

“I can’t say enough about how special it feels to be back in Corvallis again,” he said.

Riley was among several candidates athletic director Bob De Carolis interviewed, including Boise State coach Dan Hawkins. De Carolis said he made one offer — to Riley.

When Riley took over at Oregon State in 1997, he inherited a program that had won just three games in the combined 1995-96 seasons.

He was 8-14 during his tenure with the Beavers, but his recruits — including quarterback Jonathan Smith and running back Ken Simonton — found ultimate success under Erickson, who finished 31-17 at Oregon State.