The Facts: Arizona Cardinals quarterback Kevin Kolb sustained a rib injury with two minutes left in the fourth quarter of Sunday's 19-16 overtime loss to the Buffalo Bills. Kolb tried to avoid a sack and was driven to the ground by two Bills defenders. He remained on the ground for several minutes surrounded by Arizona medical staff and trainers before being helped off the field. Kolb was 14-of-26 for 128 yards and one touchdown. He also threw an interception and was sacked for a safety in the first quarter. Kolb is undergoing X-rays on his ribs. John Skelton, active for the first time since spraining his ankle in Week 1, replaced Kolb. With Kolb out, John Skelton will take the reins behind center. He's attempted 28 passes on the year and carries over experience from last season. There are worse options. Kolb has thrown for just over 1,100 yards and eight touchdowns this season. He has kept his turnovers to a minimum, allowing Arizona's stalwart defense to do most of the work. No one will mistake Kolb for a No. 1 fantasy football quarterback, but losing the top option on a 4-1 squad is tough. Despite not having dynamic numbers, he's provided leadership on offense. This is a situation to monitor moving forward. Head injuries can lead to indefinite absences, and Kolb's situation doesn't look good. With Minnesota, San Francisco and Green Bay looming in the next three weeks, Kolb's health will be important to Arizona's success.

Diehards Line:The results of Kolb's X-rays should be available sometime on Monday. John Skelton will get another shot under center should Kolb miss any time. The 4-2 Cardinals take on the 4-2 Minnesota Vikings in Week 7.