McKnight's an excellent kick returner; you don't become an excellent KOR without speed and skill in space. I may not see him as an every down back, but I do like him as a nice change of pace/third down type back. I like him on screens or as an outlet receiver. I think there's still a lot of untapped potential there.
He is also good running up the gut. It was strange, but they never worked him outside much. The used those pitches to get Greene outside on occasion (not last year) but never tried to get McKnight outside. He might work well as a catch the dump off/ line up slot/ take the draw play back. It would be scary to have him as our #1, but he *might* be successful.