Mike Matheny retires from baseball

SAN FRANCISCO, Feb. 2 (UPI) -- San Francisco's Mike Matheny has retired from the Giants after symptoms of a concussion lingered through the off-season.

He missed the final four months of the 2006 season because of a concussion.

Three weeks ago, doctors at the University of Pittsburgh diagnosed him with post-concussion symptoms and refused to clear the 13-year veteran for the 2007 season.

"I didn't expect this. I don't think anybody did," the 36-year-old Matheny told the Contra Costa Times. "There's no protocol to handle something like this, but the organization has been behind me the whole time."

"Mike is one of the toughest competitors that we have ever witnessed and a true leader," said Giants general manager Brian Sabean.

Matheny was placed on the voluntary retired list.

The three-time Gold Glove winner has a career batting average of .239 with 67 home runs and 443 RBI.

In 2006, he had only 160 at-bats, hitting .231 with three homers and 18 RBI.