Logan is expected to start in the Eagles' base defense, which could be on the field a good deal Sunday because the Raiders often employ a two-running back offense. And as Chip Kelly explained Wednesday, parting with Sopoaga also meant giving Clifton Geathers and Damion Square more snaps.
But Logan, drafted in the third round this year, is clearly the defensive lineman the Eagles most want to see at nose tackle. Despite averaging 26 snaps in the first four games, his number of plays dipped to 17 since.
Vinny Curry's increased time has been one reason Logan saw less of the field, but the production hasn't really been there either. He's recorded two sacks, mostly because of pressure created by others, and hasn't had a consistent push against the run.
Logan's growing pains were to be expected. Typically he would have had a year and an offseason to blossom at a position that requires great strength.
While Sopoaga played the traditional nose tackle role with the Eagles, either lined up directly over the center in the zero-technique or slightly off his shoulder in the one-technique, Bill Davis' defense values versatility up front. Logan has played as much at defensive end.
"In the scheme we play, every position on the defensive line is pretty much the same. Everybody does similar jobs," Logan said. "A traditional nose tackle, you'll have a big guy - 330 pounds or something like that - but in our defense we do so many different kind of things, it really doesn't matter who plays nose. Sometimes even Vinny Curry will play nose."
The 6-foot-2, 309-pound Logan isn't especially large for a nose tackle. But he has long arms (34 inches) and Kelly has placed great emphasis on that trait when evaluating players, especially up front.
"Offensive football is body on body, defense football is body off body," Kelly said. "You want to get off of blocks, and it's very difficult if you've got alligator arms and you're in here because you're going to get locked up. You need to get extension. You need to destroy blocks, and one of the ways to do that is to have long arms."
Logan said his arm length surprises offensive linemen and catches them off balance. The 6-foot-8 Geathers has abnormally long arms (38 inches). He had his best game last week against the Giants, recording three stops against the run in only 14 snaps.
Square, an undrafted rookie, dressed the first two games but was a playing-time casualty when Curry's performance warranted more action.
While dealing Sopoaga creates opportunity for a young cast of linemen, the Eagles didn't pay him $3.25 million over eight games to move up only a few spots in the draft (the Patriots gave their fifth-round draft pick for the Eagles' sixth).
The Eagles likely would have preferred at least a year with Sopoaga as they groomed Logan. Trading the former 49er did save the Eagles $1.5 million. Teams are always looking for ways to save money in the salary-cap age, one by-product of rookies playing sooner than later.
Logan, 23, said he wants to be a pillar on defense. The rookie wore the No. 18 jersey at LSU, given to the player that most displays a selfless attitude. Logan has been quietly going about his first season, but he said he's been paying attention to current Eagles leaders Jason Avant and DeMeco Ryans.
DeSean Jackson was listed as probable on the Eagles' injury report for Sunday's game. The wide receiver tweaked his ankle during Wednesday's practice. Wide receiver Damaris Johnson (ankle), safety Patrick Chung (shoulder), and linebacker Casey Matthews (hip) were listed as questionable.
If Johnson can't play, Brandon Boykin would likely return kicks. Less certain is who would take punt returns if Jackson is either sidelined or less than 100 percent.
Chung has missed four of the last five games and Earl Wolff has started in his place. If Matthews is out, the Eagles could fill Sopoaga's roster spot by calling up linebacker Travis Long.
Michael Vick, as expected, is out with a hamstring injury. Kelly announced on Wednesday that Nick Foles will start at quarterback. Matt Barkley will be the backup.