San Francisco ? Catcher Mike Matheny has made little progress in his recovery from a concussion and will not play again this season for San Francisco.

After another series of tests and appointments with specialists at the University of Pittsburgh last week, Matheny and the Giants’ medical staff made the difficult decision that he should spend the rest of 2006 recovering to reduce the risk of further damage to his brain.

“It’s real, and I understand that, and I also understand it’s out of my hands,” said Matheny, who made the announcement Wednesday after the Giants’ 8-6 victory over the Washington Nationals. “I’m at peace with that. … It’s such a weird phenomenon: I look at myself right now and I look as normal as I ever have.”

The 35-year-old Matheny, who is on the 60-day disabled list, has been sidelined since May 31 and is still experiencing “fogginess,” memory loss, dizzy spells and headaches. He has walked into a room, for example, and not remembered why he did.

A concussion involves the violent shaking of the brain, and Matheny’s head sustained multiple traumatic incidents in a short period of time. When that happens, it takes a longer time for someone to recover, according to Dr. Micky Collins of the University of Pittsburgh Medical Center’s Sport Medicine Sports Concussion Program.

“We’ve gotten enough back to know it’s the right decision,” Matheny told the Associated Press on Tuesday. “These games wear me out. They wear me out on TV. I get foggy.”

Even the lightest of physical activity, such as household chores, has the same effect. The Giants thought Matheny might have only inner-ear damage, but tests quickly showed it was a more severe problem.

“This does not mean his career is over,” trainer Stan Conte said. “It means we need more time for the symptoms to subside. Every time we have tried to increase his activity, the symptoms have come back. We’re not going to put him at risk.”

A four-time Gold Glove winner – including last season in his first year with the Giants – Matheny was hit in the head several times by foul balls during a three-game series at Florida – the last one square on his chin.

“We’ve made a very informed decision and have really covered every base and done the appropriate tests,” Collins said.