Ravens wide receiver Steve Smith Sr. tweaked his knee while running a route in practice Thursday and was listed as a limited participant.
Starting left tackle Eugene Monroe, who is dealing with a shoulder injury, missed practiced for a second straight day, putting his availability for Sunday's game against the San Diego Chargers further in doubt.
Monroe was one of three Ravens to miss practice. The other two were wide receiver Breshad Perriman (knee) and rookie cornerback Tray Walker (concussion). Neither are expected to play Sunday.
Offensive guard Kelechi Osemele (knee), tight end Maxx Williams (knee/ankle) and safeties Kendrick Lewis (knee) and Terrence Brooks (thumb) are practicing for a second straight day, which bodes well for their chances to play Sunday.
All four were listed as limited on Wednesday's injury report.
If Monroe can't play Sunday, second-year player James Hurst would start his fourth game this season.