Kellen Winslow has called for the NFL to ban low hits to reduce the chance of players sustaining serious knee injuries.
Miami Dolphins tight end Dustin Keller sustained a triple ligament tear and knee dislocation when Houston Texans safety DJ Swearinger went in low to avoid breaching the league's rules on high tackles.
The New York Jets tight end told the New York Daily News: "It's just the way he was hit, he's defenseless.
"I've been thinking about that [type of] hit for years. The guy's defenseless, and the [defender] is knifing in at his knees. That's not cool.
"That hit should be illegal. You shouldn't be knifing in at a guy's knees when they're not able to protect themselves."
Winslow joined the Jets following Keller's move to the Dolphins earlier this year.