Detroit Lions tight end Shane Zylstra suffered suffered a season-ending knee injury during Monday's training camp practice, the Free Press confirmed on Monday evening.
A person familiar with the diagnosis but not authorized to speak publicly about Zylstra's health said it is not an ACL tear.
NFL Network's Ian Rapoport was first to report the news.
Zylstra injured the knee when cornerback Khalil Dorsey hit him low near the end of practice. Zylstra limped off the field after the play.
Cornerback Cam Sutton immediately threw his hands up and grabbed his helmet as if to say, "Oh no" while safety C.