Allen was listed as the starting free safety last season, but defensive coordinator Juan Castillo has labeled Allen the strong safety this season even though his responsibilities are essentially the same.
"The safety positions are interchangeable, so the names don't really mean much," Castillo said.
Castillo lost another defensive tackle to injury when Brandon Collier left practice early with an ankle injury. Trevor Laws (hip) and Antonio Dixon (knee) have missed the last two days, and Cedric Thornton (knee) sat out Saturday.
Mike Patterson, meanwhile, remains inactive even though the defensive tackle was released from Lehigh Valley Hospital on Friday. Patterson, who suffered a seizure during Wednesday's practice, is still undergoing tests, although the team has said he has a treatable brain condition, arteriovenous malformation (AVM).
Also on defense, safety Marlin Jackson (groin), cornerback Jorrick Calvin (shoulder), and cornerback Brandon Hughes (knee) remained on the injury list. Wide receiver Sinorice Moss left Saturday's practice with a groin injury.
Tackle Winston Justice (knee) and defensive end Brandon Graham (knee) remain on the physically-unable-to-perform list and are still rehabbing their injuries.
Another offensive lineman jumped on the merry-go-round at right tackle Saturday. This time, it was recently acquired Ryan Harris.
With Justice, the incumbent, injured, offensive line coach Howard Mudd has had four linemen at right tackle since the start of camp. First it was King Dunlap; then it was Austin Howard; and, as recently as Friday, it was Fenuki Tupou.
But only Harris has extensive experience as a starter - 34 career starts with the Broncos. The Eagles signed the 26-year-old free agent to a one-year contract on Tuesday. By Saturday, he was with the first team.
"It's just been a couple of days here, but I will tell you he's an impressive young man," offensive coordinator Marty Mornhinweg said. "You can tell that he has experience and that he's played at a high level before. He's quick, he's athletic, and he's strong."
The 6-foot-3, 310-pound Harris was especially sharp during one-on-one drills, manhandling defensive end Jason Babin on back-to-back pass rushes. He also stuffed end Juqua Parker in an 11-on-11, two-minute drill.
The defense had a standout during one-on-ones in defensive tackle Cullen Jenkins, who slipped easily past guard Todd Herremans once and center Jason Kelce once.