A magnetic resonance imaging exam Friday confirmed that wide receiver Jacoby Jones has a sprained right knee, according to ProFootballTalk.com.
It's reportedly a sprained medical collateral ligament (MCL), which means Jones will miss four to six weeks.
ProFootballTalk.com's Mike Florio says the prognosis means Jones' MCL is likely frayed and can be healed without surgery. He simply needs rest.
Jones suffered the injury when rookie safety Brynden Trawick collided with him when Jones was trying to field a punt. Jones signaled for a fair catch and Trawick never saw him.
With Jones out, the Ravens lose speed on the outside of their offense and perhaps the most dangerous returner in the NFL.
Rookie wide receiver Marlon Brown stepped in on offense in Denver, and caught four passes for 65 yards, including a 13-yard touchdown. The undrafted rookie out of Georgia has been impressive whenever he's run with the starters.
Backup running back Bernard Pierce became the Ravens' kickoff returner in Denver with Jones out. Cornerback Lardarius Webb stepped in as punt returner.
With Jones now reportedly out for an extended period of time, the Ravens could make some corresponding roster moves.
They also have wide receivers Aaron Mellette and Deonte Thompson. Mellette was a healthy scratch Thursday night and Thompson is making progress from a sprained left foot that has kept him out since Aug. 8.