Rookie Eric Reid was named the San Fransisco 49ers' starting free safety for the team's Sept. 8 regular-season opener by defensive coordinator Vic Fangio.
The first-round pick won a training camp battle with veteran Craig Dahl to replace Dashon Goldson, who signed with Tampa Bay as a free agent.
"He's gotten better and better each and every day," Fangio said of Reid. "He's had his potholes in there where he's had some mistakes here and there. Overall he's just been steady. He's grown in the position, which has allowed his ability to come through more and more. He's tackled well in the games which is important for us."
Meanwhile, wide receivers Michael Crabtree (Achilles) and Mario Manningham (knee) will officially miss at least the first six weeks of the season after being placed on the physically unable to perform list. Once they return to practice, the 49ers will have a 21-day window to either activate them or place them on season-ending injured reserve.
The team also waived/injured Lawrence Okoye (right knee) and Lamar Divens.
"Relax people - I'm going on IR," Okoye tweeted after the move was announced.
Harbaugh said Okoye's injury wasn't likely to sideline him from football activity for the full season and "we can sign him back" once he's healthy.
Cornerback Chris Culliver, who suffered a season-ending knee injury during training camp, was placed on injured reserve.
Cornerback Eric Wright, defensive linemen Tank Carradine and Quinton Dial, offensive tackle Luke Marquardt and running back Marcus Lattimore were placed on the reserve/non-football injury list.
Wright, who was signed Aug. 8, reported to the team Tuesday and was seen working out. His exact condition has not been disclosed, but he did deal with an Achilles injury while with Tampa Bay last season. Wright has also had to deal with some off-field matters.
--Cornerback Nnamdi Asomugha had the inside track on the No. 3 cornerback job over Tramaine Brock, but Fangio said Asomugha is now "nursing a little injury," leaving the position unsettled. Brock has been dealing with an injury as well.
--Linebacker Joe Holland was re-signed. He was claimed by the 49ers off waivers from Tampa Bay on Aug. 22 and released Monday.