LAKE FOREST, Ill. -- Chicago Bears rookie wide receiver Alshon Jeffery underwent arthroscopic surgery on his right knee Wednesday morning, head coach Lovie Smith confirmed.

Smith said the Bears expect to have Jeffery back on the field in 2-4 weeks.

Jeffery hurt the knee in the Bears' 32-7 loss to the San Francisco 49ers and spent the fourth quarter on the team's bench with his right knee wrapped in ice. The second-round pick gave the impression his injury wasn't serious when he jogged back to the visitors locker room with his helmet on after the game, but clearly that wasn't the case.

This is the second injury of the season for Jeffery, who fractured his right hand in the Bears' win over the Jacksonville Jaguars on Oct. 7 and missed the next four games before returning against the 49ers.

"Alshon will bounce back," Bears receiver Brandon Marshall said. "Just like I told him in the cafeteria a few minutes ago, in the offseason he’s gonna be in Florida with me. He’s gonna be working out with me because a lot of that is really getting your legs under you. It’s tough as a rookie going from bowl games to training for the draft and training for minicamps, going to minicamps early. So it’s really tough. I think this year, I think us working together in the offseason will really help him stay a little healthier and get those bones a little stronger. Again, I think we’ll have him back before the end of the season and he’ll definitely help us out when he gets back.

Jeffery has 16 catches for 199 yards and two touchdowns on the season.