Patriots rookie DE Derek Rivers tears ACL

The Patriots may have suffered their first significant injury of the season Wednesday when rookie Derek Rivers hurt his knee.

The Patriots fear Rivers suffered a season-ending knee injury in Wednesday’s joint practice with the Texans. The rookie out of Youngstown State suffered the injury on a kick return drill and walked off the field with head trainer Jim Whalen, but didn’t return. He reportedly didn’t fly to Houston with the rest of the team and instead flew back to Boston.

According to NFL Media, an initial MRI revealed Rivers tore his ACL and sprained his LCL, per a source informed of the situation. The rookie will get a second opinion to confirm surgery is needed.

With Rivers’ injury, the Patriots are very thin on the defensive line right now. Trey Flowers and Kony Ealy are listed as the two starting defensive ends on the team’s depth chart, and Rivers is Flowers’ backup, with Caleb Kidder as third-stringer.

Other injury notes on Friday:

1. Atlanta Falcons wide receiver Julio Jones will not play Sunday vs. the Steelers. The receiver is still recovering from offseason foot surgery.

2.  Cam Newton will not play in the Carolina Panthers’ preseason game against the Titans on Saturday as he recovers from offseason shoulder surgery. The quarterback, though, is throwing more and feels fine.

3. Pittsburgh Steelers linebacker Ryan Shazier (hamstring) returned to practice.

4. Tampa Bay Buccaneers offensive tackle Demar Dotson suffered a groin injury against the Jacksonville Jaguars on Thursday and will undergo an MRI on Saturday.