Ravens continue to be short-handed along offensive line

(Updated: 6:25 p.m.)
OWINGS MILLS, Md. — Practicing indoors on Thursday afternoon, the Ravens were without an additional member of the projected starting offensive line as left guard Bobbie Williams was not present for the opening portion of practice.
It was unclear whether the 35-year-old lineman was receiving a day off as he became the third member of the starting line that wasn’t practicing. Left tackle Bryant McKinnie and center Matt Birk were not working as the Ravens conducted practice in helmets, shells, and shorts, but the two later walked out to the field to watch practice.
McKinnie is dealing with a lower back injury and has yet to pass his conditioning test to clear him to participate in workouts. Birk was not practicing for the fourth straight day, creating more questions after John Harbaugh explained Tuesday that the 36-year-old would receive frequent days off during camp.
Defensive tackle Haloti Ngata remains on the active physically unable to perform list as he continues to recover from a hamstring injury. Other absent players included linebackers Courtney Upshaw (shoulder) and Josh Bynes (undisclosed), wide receivers Tandon Doss (hamstring) and Patrick Williams (undisclosed), running back Bernard Pierce (hamstring), and offensive lineman Jah Reid (calf).
Defensive end Arthur Jones was a new addition to the list of non-participants while wide receiver Anquan Boldin was present but appeared to be receiving a day off after warming up but not taking part in positional drills.
Offensive lineman Cord Howard (knee) returned to practice after missing Wednesday’s workout.
Tight end Dennis Pitta (broken hand) attended practice and had his right hand heavily wrapped after undergoing surgery earlier this week. He will miss the rest of the preseason, joining wide receiver David Reed (knee) and linebacker Terrell Suggs (Achilles tendon) as long-term injury concerns for the Ravens.