That means a defensive secondary that already had depth issues going into the season probably will face Philip Rivers without one of its starting corners.
"Day to day," defensive coordinator Bill Davis said of Fletcher, which is what coaches usually say when the injured player still has a pulse and no bones have broken through the skin.
"We're lucky we've got Brandon Hughes back. So we have to see where Brandon is and where Fletch is. We will prepare in practice for all plans if Bradley doesn't play. Right now, we [still] hope he will."
Hughes, who broke a bone in his hand 3 weeks ago, was released by the team late last week and re-signed this week. His re-signing would have happened even if Fletcher hadn't gotten hurt.
If Fletcher can't play, Brandon Boykin, the team's capable nickel corner, who had one of the Eagles' two interceptions against the Redskins, will move outside to right corner in the team's base defense.
"We'll practice it a couple of different ways, but that would be our first move, probably," Davis said.
When the Eagles use their five-defensive back nickel package, Boykin probably would move back inside and Hughes would play outside along with the team's other starting corner, Cary Williams.
Boykin said he took snaps inside and outside yesterday in practice.
"That's a decision the coaches will make later on in the week," he said. "But both of us are capable of playing nickel. Both of us are capable of playing corner.
"It probably will be based off of what they feel [the Chargers] will run the most, be it [three wide receivers, one back, one tight end], where we have to go to nickel a lot. We're still learning the game plan."
The Chargers favor three-wide-receiver sets. They used them on 69 percent of their offensive plays in Monday night's come-from-ahead loss to Houston. They'll likely use them at least that much Sunday, particularly if Fletcher doesn't play.
Hughes, 27, played only 64 defensive snaps last year, and 91 the year before. And he's coming off an injury that has sidelined him for 2 1/2 weeks.
It's only natural that Rivers and the Chargers would go after him, much as the Redskins' Robert Griffin III did Monday with rookie Jordan Poyer, when Williams missed a series in the fourth quarter with cramps.
"I'm just out there competing and getting myself back into football shape," Hughes said. "I've been out almost 2 1/2 weeks. I don't really know what they're planning on doing."
It's possible Davis might leave Boykin on the outside in nickel and play Hughes inside. But Hughes didn't sound as if that was a likely scenerio.
" 'Boyk' is a natural slot guy," he said. "You don't want to mess with that. I can do both. I do what I'm called on to do. That's my philosophy. I just need to work myself into shape, so I can do what I'm called on to do."
Boykin had hoped to challenge for a starting corner job this summer. But the Eagles didn't sign Williams and Fletcher in free agency to have them sit the bench.
The coaches also seemed to have some reservations about putting the height-challenged Boykin, only 5-9 1/2, outside against bigger receivers, even if he does have a 41-inch vertical leap.
"Hopefully, [Fletcher] will be back," Boykin said. "But if not, I'm preparing to play outside and inside. That's why the coaches have us practice at multiple positions, because the pace of the game is so fast and we're going to have injuries throughout the year. So you have to be ready."
Williams, who also had an interception in the win over the Redskins, said he is confident Boykin can get the job done outside if Fletcher can't play.
"No question," he said. "I have nothing but the utmost faith in that guy. I think we have great depth and we can show that this Sunday."
On Twitter: @Pdomo