Practice summary: Practice began on a somber note with cornerback Chris Culliver going down with a potentially serious left knee injury while running down the field in a punt coverage drill.
Several of his teammates consoled Culliver, who also received a hug from 49ers general manager Trent Baalke. Culliver, a vital part of the 49ers' defense as the No. 3 cornerback last season, was crying as he was carted off the field.
He was driven to Stanford Hospital, where he underwent an MRI examination, 49ers coach Jim Harbaugh said.
Shortly after Culliver's injury, a couple of the team's non-starting cornerbacks made plays. Perrish Cox intercepted a pass from backup quarterback Colt McCoy. And veteran Nnamdi Asomugha had his second consecutive strong day of practice with passes broken up against wide receivers Marlon Moore and Chad Hall on consecutive plays.
Offensive play of the day: During an 11-on-11 drill, rookie receiver Quinton Patton caught a pass from Scott Tolzien on a 10-yard hitch pattern. It was really nothing spectacular, other than the fact that Patton is not allowed to catch passes due to an injury to the middle finger on his left hand. Patton seemed to almost reluctantly catch the pass. As he came back to the offensive side of the ball, coach Jim Harbaugh had some words with Patton. Harbaugh then looked at 49ers head athletic trainer Jeff Ferguson and shrugged his shoulders.
[REWIND: Patton follows orders, lets passes drop]
Defensive play of the day: Quarterback Colin Kaepernick tried to fit in a pass to tight end Vernon Davis late and over the middle, and rookie linebacker Nick Moody got his hands on the ball. The ball deflected to fellow inside linebacker Michael Wilhoite, who recorded the interception. Wilhoite and Moody got reps with the first team with Patrick Willis (broken hand) and NaVorro Bowman (groin) sidelined.
[RELATED: Willis, Bowman backups take center stage]
Other highlights: Moore made a nice play to hold onto a 17-yard out pattern against cornerback Carlos Rogers despite a collision at the sideline. . . . Backup tackle Kenny Wiggins supplied the block of the day when he drove defensive lineman Lawrence Okoye five yards down the field on a Jewel Hampton running play and planted him on his back. . . . TE Vernon Davis was split out wide on two plays in practice. On the first, he motioned wide left and was covered by Moody. On the second play, Asomugha went out with him. Both plays were runs.
On the sideline: The 49ers had 16 players on the sideline for practice, including Culliver. Willis had a black cast on his fractured right hand. Harbaugh said Willis will be ready to play Week 1 against the Green Bay Packers on Sept. 8. Bowman sat out with a groin strain.
Others who did not practice on Thursday due to injuries: C Jonathan Goodwin, OLB Aldon Smith, OT Carter Bykowski, WRs Kyle Williams, A.J. Jenkins and Kassim Osgood.
WR Michael Crabtree (Achilles), RB Kendall Hunter (Achilles), WR Mario Manningham (knee) are on the active PUP list. RB Marcus Lattimore (knee), DE Tank Carradine (knee), DT Quinton Dial (toe) and OT Luke Marquardt (foot) are on the active non-football injury list.
Scouting wideouts: The 49ers brought in veteran wide receivers Laurent Robinson and Austin Collie for workouts. Robinson, who sustained four concussions last season, appeared in just seven games with the Jacksonville Jaguars. Collie played one game for the Indianapolis Colts prior before sustaining a torn patellar tendon.
Roster move: LB Darius Fleming, who sustained a torn ACL in his left knee on Sunday, cleared waivers and reverted back to the 49ers. He is on injured reserve for the season.
Quote of the day: "This kid has come a long way. I don't care what you say, I want him on my team."
--49ers tight end Vernon Davis, referring to linebacker Michael Wilhoite, who was speaking with reporters at the time.