SANTA CLARA, Calif. -- San Francisco 49ers free safety Eric Reid has an idea as to what new teammate and strong safety Antoine Bethea is going through this week as he undergoes the NFL-mandated concussion protocol after being injured Sunday."I can definitely relate," Reid said this week. "It happened to me twice last year."Indeed, Reid suffered two concussions as a rookie, in a Week 2 loss at the Seattle Seahawks and in the 49ers' ninth game of the season, a Nov.