Chicago Bears quarterback Caleb Williams has been diagnosed with a Grade 2 hamstring strain that doctors believe will keep him out three to four weeks, ESPN’s Adam Schefter and Ian Rapoport reported Sunday. The injury, suffered on a non-contact scramble in Week 2 against the Minnesota Vikings, has already ruled Williams out of Monday night’s home game against the Philadelphia Eagles and could sideline him through mid-October.

Williams exited early in Chicago’s 9-3 loss to the Vikings on September 20, finishing the day 15-of-26 for 138 yards and an interception before leaving with the hamstring issue. Head coach Ben Johnson had spent the week publicly hedging on a timetable, calling the imaging results “somewhat encouraging” while still labeling his third-year quarterback week-to-week. The Schefter and Rapoport report puts more specific numbers on that vague outlook, and the Bears have not placed Williams on injured reserve, which would require a minimum four-game absence.

What a Three-to-Four Week Absence Means for Chicago

A three-week absence would cost Williams the Eagles game, a Week 4 matchup with the New York Jets and a Week 5 trip to face the Green Bay Packers, setting up a possible return in Week 6 against the Atlanta Falcons on October 18. A four-week absence would push that return back past the Falcons game entirely. Doctors’ estimates for Grade 2 strains are exactly that — estimates — and Johnson has repeatedly noted that Williams has historically healed faster than expected, but the team is clearly not rushing a rebuilt hamstring back onto the field for a division race that is still finding its footing at 1-1.

The bigger complication is who lines up under center in the meantime. Backup Tyson Bagent is questionable for Monday night with a concussion, which has pushed veteran Case Keenum into first-team reps for most of the week. Keenum, a 14-year NFL veteran with starts scattered across seven different franchises, gives Chicago a stable hand but not much of the dual-threat dynamism that has defined Williams’ game since he entered the league as the No. 1 overall pick. Through two games this season, Williams had thrown for 407 yards and two touchdowns with one interception while adding 107 yards and two rushing scores, numbers that had Chicago’s offense trending in the right direction before the injury.

Odds Have Already Moved Hard Against the Bears

The betting market reacted well before Sunday’s official diagnosis. Chicago opened as a 1.5-point home favorite over Philadelphia in the lookahead line before Williams’ injury became public, according to line-tracking reports. Once his absence looked likely, that number swung by a full six points, with the Eagles moving as high as 4.5-point road favorites and moneyline prices settling around -235 to -240 for Philadelphia against a Bears price in the +182 to +194 range, depending on the sportsbook. The total also cratered, falling from an opening line near 46.5 or 47.5 down into the 41.5-to-44.5 range as oddsmakers priced in a far less explosive Chicago passing attack.

One sportsbook executive told Sports Illustrated that the market has effectively valued Williams at roughly six points to both the spread and the total on his own, a striking figure that underscores how central he’s become to Chicago’s offensive identity in a short amount of time. With Bagent’s concussion designation adding another layer of uncertainty behind Keenum, that line could still see further movement as game day approaches, particularly if Chicago’s practice reports this week clarify who actually takes the snaps. For bettors watching futures markets, the timeline also raises questions about Chicago’s playoff and win-total outlooks over the next month, given the murky quarterback situation the team now faces heading into a stretch against the Eagles, Jets and Packers.