Vikings left tackle Matt Kalil reportedly underwent a series of medical procedures on both knees earlier this offseason.
According to Tom Pelissero of USA Today, Kalil had arthoscopic surgery on both knees in January, then later had treatment in which blood was removed, then re-injected into the knee. He also received platelet-rich plasma treatment in the knees.
The 25-year-old Kalil has never missed a game in three NFL seasons, but he did have knee surgery last offseason, and he dealt with swelling in a knee in 2014, USA Today reported.
The Vikings have exercised their 2016 option on Kalil, the No. 4 overall pick three years ago. However, he had trying 2014 season. Per STATS LLC, Kalil gave up more sacks a season ago (13.75) than he had allowed in his first two seasons combined (11).
