SANTA CLARA After tearing through the Chicago Bears' offensive line Monday night, Aldon Smith was given a reward Wednesday.
The NFL named him the NFC Defensive Player of the Week for his 5 1/2-sack performance, which moved him into the league lead with 15. The linebacker also was given one of three defensive game balls by coach Jim Harbaugh.
The other two went to Justin Smith and Patrick Willis as the 49ers held the Bears to the second-fewest total yards (143) in the NFL this season.
"He used a lot of different moves to make those sacks a bull rush, great athleticism, great balance," Harbaugh said of Aldon Smith. "Used his arm one time as a leg to stay up. It was really awesome to see."
Aldon Smith also was credited with seven quarterback hits and two forced fumbles, one of which led to a safety. That he did it on national television likely means Smith is in the running for the Defensive Player of the Year award.
Last year, Smith was the runner-up to Denver linebacker Von Miller for NFL Defensive Rookie of the Year. Smith leads Miller by two sacks with six games remaining.
Rachal exits Two days after the Bears' offensive line gave up six sacks to the 49ers, Chicago left guard Chilo Rachal left the team for personal reasons.
Rachal spent his first four seasons with the 49ers, but the team didn't make an offer when he became a free agent. Rachal, a second-round pick in 2008, began the 2011 season as San Francisco's starter at right guard but eventually was replaced by Adam Snyder.
He reportedly became upset this week when he was notified he would be replaced in the starting lineup by Chris Spencer. The Bears had protection breakdowns across their line Monday, but Rachal had a particularly tough matchup with defensive end Justin Smith.
He twice was called for holding, and he was tackled in the end zone for a safety after recovering a fumble.
Per league rules, Rachal has five days to return to the team or he won't be able to return this season.
Injuries Four 49ers went through a limited practice Wednesday: cornerback Tarell Brown (knee), cornerback Chris Culliver (shoulder), safety Dashon Goldson (ribs, calf) and quarterback Alex Smith (concussion).