PHILADELPHIA (973espn.com) — We're now less than three weeks from the Eagles' regular-season opener against the Washington Redskins and plenty of the team's key contributors on defense are still question marks.

All-Pro defensive tackle Fletcher Cox and cornerback Jalen Mills still haven't hit the practice field after foot surgeries and others like linebacker Nigel Bradham (toe surgery) and Ronald Darby (ACL) have mixed back in but wouldn't be ready for Case Keenum and Co. if kickoff was tomorrow.

The good news for Jim Schwartz is the Week 3 preseason matchup with Baltimore is on tap Thursday and there's still time for his rehabbing players.

In the case of Cox and Darby, it seems like Philadelphia is simply being extra cautious but the former was generally on the field rehabbing during practice early in camp and that hasn't been the case recently although both the organization and Cox have said there has been no setback and Week 1 remains the goal.

Darby has progressed to the point he's been back in team drills but is anxious to drop a bulky brace the medical staff is forcing him to wear.

Bradham just returned to 7-on-7 work on Sunday but set off an alarm Tuesday when he admitted to the Philadelphia Inquirer that he's "not really" close to getting involved in team drills and a Week 1 goal may not be reasonable.

“I just have to get comfortable, real comfortable, with my feet," he said. “I’ve got to get my power back and stuff like that.’’

Without Bradham and the injured Kamu Grugier-Hill, who is already expected to miss multiple weeks in the regular season with a Grade 3 MCL sprain suffered earlier in training camp, Nate Gerry and former Redskin Zach Brown have been the first-team nickel LBs. With the Ravens, a heavy rushing team, in for joint practices more base defense was used and L.J. Fort joined the group as the MIKE LB.

As for Mills, the regular-season PUP list to start is still the most likely scenario although Doug Pederson failed to give up hope on Tuesday.

“I don’t know yet. Right now, he’s doing extremely well in his rehab, I can tell you that,” Pederson said. “The updates have been really good for where he’s at. ... We’re confident he’ll be ready to go. ... Maybe, we’ll see. But he’s doing really well.”

Interestingly, Schwartz made a tweak against Baltimore at CB with Darby flipping sides to left cornerback and Sidney Jones playing RC with Avonte Maddox in the slot. Those are the three likely starters for Week 1 with positioning being the only question.

There is better news on the offensive side where Pederson was more concrete in expressing the belief that right tackle Lane Johnson (knee) and tight end Dallas Goedert (calf) will be a go for Week 1. Both were ruled out of the preseason after the Eagles’ first preseason game against the Tennessee Titans.

Right guard Brandon Brooks (Achilles') is back doing individual work at practice and has been in group install work consistently but the hope of being cleared for full practice a week ago did not materialize.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen