San Francisco linebacker Ahmad Brooks, out since Aug. 6 with a lacerated kidney, will miss the 49ers' season opener Sunday against the Seattle Seahawks.
Brooks sustained the injury during individual period on the sixth day of training camp when he threw down a blocking sled and it bounced off the ground and it struck him on his left side. A rib pierced his kidney. He said the injury is 90-percent healed.
Veteran Travis LaBoy will likely take over Brooks' role last season as a third-down pass rusher. Brooks moved into that job late last season, and ended up ranking tied for second on the team with six sacks.
Brooks is not expected to be available until at earliest the second game. He is scheduled to be examined later in the week. He hopes to return to full practice next week and suit up for the 49ers' Monday night game, Sept. 20, against the New Orleans Saints.