SAN FRANCISCO -- The San Francisco 49ers released wide receiver and return man Kyle Williams, son of White Sox executive Kenny Williams, on Tuesday after three-plus seasons, while also waiving cornerback Perrish Cox.
Linebacker Nick Moody was activated from the injured reserve/designated for return list Tuesday. The rookie returned to practice Oct. 23 for the first time since Week 1, when he went on injured reserve with the designation to return after breaking his hand. Moody is a sixth-round draft pick who transitioned from playing safety.
"Decisions like these are always difficult, especially at this time of year," 49ers general manager Trent Baalke said. "Kyle and Perrish have represented the 49ers organization very well, both on and off the field. We appreciate their dedication and contributions and wish them all the best."
Williams' agent, Wynn Silberman, was told of the move Tuesday by the reigning NFC champions.
"We're looking forward to the opportunity to compete within the league somewhere this year," Silberman said. "We're very appreciative of the San Francisco 49ers organization for the opportunity to contribute."
Williams missed last season's run to the Super Bowl -- a 34-31 loss to the Ravens -- because of a serious knee injury but remained a key member of the team and was honored with the team's Ed Block Courage Award.
San Francisco (6-3) is looking for more production in the passing game, and Williams had fallen on the depth chart with the return of Mario Manningham for Sunday's 10-9 loss to the Carolina Panthers.
In addition, 2012 leading wideout Michael Crabtree resumed practice last week for the first time since undergoing surgery in May for a torn right Achilles tendon. Coach Jim Harbaugh wouldn't say whether Crabtree might be ready in time for Sunday's game at New Orleans (7-2).
The 25-year-old Williams, a native of nearby San Jose, has 12 catches for 113 yards and no touchdowns this season after beginning the season as the No. 2 receiver opposite Anquan Boldin. On special teams, he had 12 punt returns for 61 yards and seven kickoff returns for 134 yards.
A sixth-round pick by the 49ers in the 2010 draft out of Arizona State, Williams returned this season from a torn anterior cruciate ligament in his left knee that required surgery and ended his 2012 season in late November. Just when Williams was on a nice roll last year, he got hurt in a Nov. 25 win at New Orleans. He had 13 catches for 212 yards and a touchdown in the first 11 games of 2012.
Williams dedicated this season to former Sun Devils teammate, Tyrice Thompson, who died Feb. 2 from injuries suffered when he was stabbed Jan. 27 while working at a popular Scottsdale, Ariz., nightclub. Williams added a No. 81 tattoo on his inner left forearm to honor Thompson.
Williams will long be remembered for his two costly fumbles in a 20-17 overtime loss to the New York Giants in the NFC Championship Game following the 2011 season. That included losing a fumble on a punt return in overtime that set up Lawrence Tynes' winning field goal. Williams -- who had a concussion late in the 2011 season -- immediately took responsibility for the mistake, but received death threats and was harassed on social media.
"I learned a lot of things from Kyle," running back and returner LaMichael James said. "I don't think you can judge him on one or two games. He's done a lot of great things. I'm just trying to pick up the slack and do it for my team."
In April 2012, a recording came out of former Saints defensive coordinator Gregg Williams instructing players in January to "put a lick" on Kyle Williams to see if he had lingering effects from a concussion. The NFC West champion 49ers beat Drew Brees and favored New Orleans 36-32 in the NFC divisional playoffs. Gregg Williams oversaw and contributed money to the illegal bounty fund for planned vicious hits on opponents.
The 49ers vowed to stick by Williams and keep him around, and Harbaugh and Baalke did just that and gave him a fresh start last season.
James served as the punt returner Sunday for the first time, though Harbaugh didn't say if he would do so against the Saints.
James had been inactive for the previous three games.
"It's something I can get better at each and every week," James said. "It's something I've got to grow at, but it was fun. It meant a lot (to be back). I got the feel back just going out there and playing."