Patriots rookie Derek Rivers may have season-ending knee injury

New England Patriots defensive end Derek Rivers (95) steps on the field at NFL football training camp, Thursday, July 27, 2017, in Foxborough, Mass. (AP Photo/Steven Senne)
Derek Rivers was taken by the Patriots in the third round, No. 83 overall. –Steven Senne / AP

HOUSTON — The Patriots may have their first significant injury of the season, as rookie defensive end Derek Rivers suffered what could be a season-ending knee injury Wednesday.

A league source confirmed Friday the possibility that Rivers has a torn left ACL and a sprained LCL, which had been reported by NFL Media.

The source said no final diagnosis had been made. Rivers will have a second MRI before any call is made on whether he will have surgery or require only rehab.