LANDOVER, Md. – Cornerback Ronald Darby, acquired in a trade early in the preseason to beef up a thin position, went down with an ankle injury in the second quarter of Sunday's 30-17 win over Washington and there is no official word on how long Darby will be out. The Eagles' secondary stepped up and finished the job against a potent Washington passing game in Darby's absence.

Darby's right foot planted in the turf at FedEx Field right in front of the Eagles' bench with 12:06 remaining in the second quarter on a play that saw Washington quarterback Kirk Cousins scramble and break into the open for a 4-yard gain.

The Eagles immediately reacted once they saw Darby on the ground. Darby was then carted off the field as the athletic training staff appeared to put an air cast on his foot and ankle and ruled out for the remainder of the game.

"It was tough to see him go down, but we had to rebound and I think we did that," cornerback Jalen Mills said. "He's our brother and we're going to be with him no matter what the injury is like. He's going to come back at some point. Until he does come back, we have to fill in around him.

"He is one of us and he's been out here grinding with us, making plays. Once he was hurt, we all rallied around him. Not just the defense, but the entire team. We wanted to win this game for him."

How long Darby will be out remains to be seen, but his absence certainly creates a void for the Eagles. With Darby sidelined, Patrick Robinson played left cornerback and Jalen Mills remained at right cornerback. Malcolm Jenkins played in the slot at times, and Jaylen Watkins and Corey Graham saw important defensive reps, Watkins at cornerback after moving to safety in the offseason.

"I knew I was going to play at some point, but I didn't think it would be cornerback first," Watkins said. "It was a good experience for me. I held my own out there, played hard. I've got to refine my technique and keep getting better and stay ready for every situation."

The Eagles dressed only three cornerbacks for the game, keeping third-round draft pick Rasul Douglas and newly acquired Dexter McDougle inactive. Moving forward, at least one of those players will likely be active starting Sunday in Kansas City.

Beating Washington on Sunday was a great start to the season, but the Eagles know they might have to replace Darby in the starting line up in Kansas City on Sunday at the very least.

"One man goes down and another one has to step up," Mills said. "That's the way it is around here. You can't hang your head or let it linger. You have to go out and do the job."

The Eagles did just that on Sunday, limiting Cousins to 240 passing yards and keeping a powerful Washington offense to just 264 total net yards and 10 points scored.