Kevin Kolb Battles the Storms, Outside and In

Kevin Kolb Battles the Storms, Outside and In

Kolb’s first diagnosed NFL concussion came on a tackle by Clay Matthews in the 2010 season opener. (Al Tielemans/SI/The MMQB)

Kolb’s head struck the ground as the two landed. (Al Tielemans/SI/The MMQB)

Kolb played the rest of the half, then sat out until Week 4. (Al Tielemans/SI/The MMQB)

With the Cardinals in December 2011, Kolb was sacked by the 49ers’ Justin Smith, but it was a knee to the head by another defender after Kolb went to ground that caused the damage. (Christian Petersen/Getty Images)

Kolb left that game and was out for the rest of the season. (Paul Connors/AP)

As with the 2011 concussion in Arizona, the one in 2013 preseason with the Bills came from a defender’s knee. It was Kolb’s last game as a pro. (Patrick Smith/Getty Images)