OWINGS MILLS, Md. -- Baltimore Ravens first-round pick Breshad Perriman wasn't present at the start of Monday's practice.

Perriman practiced in a limited capacity two days last week before aggravating his right knee injury in pregame warm-ups Sunday. The No. 26 overall pick, Perriman sprained his knee on the first day of training camp (July 30).

Quarterback Joe Flacco said he doesn't want to guess on when Perriman will come back.

"I honestly didn’t get to do too much with him last week," Flacco said. "I know he was out here going through a little bit of stuff, but I have no idea how he feels and what’s actually going on. I didn’t get to throw to him. It’s not something that I’m going to worry about until I know for sure that he’s coming back. Just tell me when he’s coming back. Other than that, don’t really bother me with it, because it’s not something we can worry about at this point.”

The Ravens have missed the playmaking ability of Perriman. Steve Smith is Baltimore's only wide receiver with more than six catches after three games.

The only impact rookie receiver in the league this season has been Oakland's Amari Cooper. No other rookie receiver has more than nine catches this season.

2015 first-round wide receivers

Amari Cooper (No. 4): 20 catches, 290 yards and one TD

Kevin White (No. 7): On PUP with stress fracture in shin

DeVante Parker (No. 14): Four catches for 49 yards

Nelson Agholor (No. 20): Four catches for 36 yards

Breshad Perriman (No. 26): Missed first three games with knee injury

Phillip Dorsett (No. 29): Five catches for 113 yards and one TD