SANTA CLARA, Calif. (AP) -- San Francisco 49ers tight end Vernon Davis and rookie safety Eric Reid were together in the Candlestick Park locker room, slightly groggy after each suffered a concussion during Sunday's 10-9 loss to the Carolina Panthers.
''We sat there watching the game on television,'' Davis said. ''It was frustrating because we wanted to be out there.''
Two days later, both players are optimistic about returning in time to play the Saints in New Orleans this week.
''I'm doing fine, feeling great,'' Davis said. ''All I can do is to wait for the doctors to tell me what I can do next.''
Davis and Reid each sustained their second concussion, with Davis getting hurt last year. He says it's difficult trying to balance between playing all out and being concerned with his health.
''You have to be concerned with your health, but you can't really think about it,'' Davis said. ''It's a tough spot to be in. Concussions are one of the big ones. Sometimes you're ready to make contact with someone and you're thinking about your head.''
Davis was injured midway through the second quarter, as the 49ers were driving for a score. He went up for a pass from Colin Kaepernick and hit the ground hard on what was ruled an incomplete pass. The 49ers settled for a field goal to make it 9-0.
Reid suffered his concussion when he tackled Carolina's Mike Tolbert following a 17-yard pass reception midway through the third quarter.
''I'm feeling fine,'' he said before heading off. He nodded when asked about what was expected of him this week.
Davis said he did a little weightlifting, rode a stationary ride and attended meetings.
''My memory was good. I remembered everything,'' he said. ''My balance was OK.''
David and Reid will have to pass a contact test on Thursday or Friday before being cleared to play.
Second-year tight end Garrett Celek said he's taking things day by day after sustaining a hamstring injury less than six minutes into the loss. He missed the remainder of the game.
Celek strained his hamstring during a punt return with 9:18 remaining in the first quarter.
''It was a freak thing,'' he said. ''It didn't feel right. This is the first time something like this has happened. I don't know how my body is going to respond.''
Celek tried to stretch it out by running around and getting in his stance.
''It was sore and the doctors didn't want to risk anything and they told me to sit out,'' Celek said. ''Right now I still don't know the extent of it.''
NOTES: The 49ers released WR Kyle Williams. ... The team also waived CB Perrish Cox and activated LB Nick Moody, a rookie safety and linebacker out of Florida State. ... RB LaMichael James said he was ready to step in and return kicks in Williams' absence. ''I feel like I can be a huge asset,'' he said. ''I'll leave it up to coaches and I'll do whatever they want me to do.'' ... S Eric Wright fielded some kicks along James during practice. ''It's fun to go back and catch a few balls,'' Wright said. ''I want to be prepared and ready to maximize my opportunities. I grew up playing offense and I'm used to having the ball in my hands.''
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