The San Francisco 49ers and Chicago Bears are two of the top teams in the NFC, but that's with their respective starting quarterbacks.
Concussions may make both unavailable come Monday night.
With Alex Smith and Jay Cutler potentially adding to the national viewing audience, it could be up to Colin Kaepernick and Jason Campbell to solve two of the toughest defenses in the league as the 49ers and Bears meet at Candlestick Park.
San Francisco (6-2-1) and Chicago (7-2) lead the NFC West and North, respectively, and seem destined for the playoffs. The 49ers are hoping to go one step further this time and reach the Super Bowl, while the Bears were stopped one game short the previous season.
Those aspirations have been dealt a few major blows, specifically to the heads of Smith and Cutler.
Smith was hit hard twice in last week's 24-all tie with St. Louis, leaving the game in the second quarter after overcoming blurred vision to throw a 14-yard touchdown pass to Michael Crabtree.