PHILADELPHIA (973espn.com) — The Eagles officially lost their leader on special teams Thursday when Chris Maragos was placed on injured reserve with a knee injury.

The veteran hurt himself while covering a punt in the fourth quarter against Carolina a week ago.

To replace Maragos on the roster Philadelphia promoted rookie linebacker Nate Gerry from the practice squad.

"It's hard," Eagles coach Doug Pederson said when discussing Maragos' injury. "It's [the injuries] something we have been faced with already this season and the next man step's up and fills that role."

A safety at Nebraska, Gerry was making the tough transition up a level at the professional ranks so he has some versatility in coverage. His main role, however, will be on special teams and it will be difficult to replace Maragos, who has been one of the NFL's best special teams players for years and the leader of many of Dave Fipp's coverage units.

A fifth-round pick, Gerry was released at the final cutdown and then re-signed to the practice squad after clearing waivers. He's the next man up as far as the roster goes but others will be expected to fill Maragos' actual role.

"It's got to be a little bit by committee," Pederson said. "Corey Graham will have a role in there. Jaylen Watkins is going to have a role. Corey Clement will have a role. So it's going to have to by committee as we go until we solidify with one guy."

Through six games Maragos was tied for the team lead in special teams tackles with Kamu Grugier-Hill at six apiece. He also was forced into action on the base defense during Week 3 against the New York Giants due to a plethora of injuries, recording nine tackles while playing opposite Malcolm Jenkins on the back end.

The Eagles also re-signed receiver/returner Rashard Davis to the practice squad to replace Gerry there.

In other injury news, Pederson said that middle linebacker Jordan Hicks (ankle) and running back Wendell Smallwood (knee) will be on the field in at least a limited fashion on Thursday.

Meanwhile, Ronald Darby, who dislocated his ankle in the season opener against Washington, will get some work this week although it's too early to know whether the speedy corner will be able to return Monday against the Redskins.

"I can't commit at this time if he's going to be ready (to play on Monday night)," Pederson said, "but we're going to give him some reps this week and see where he's at but he's doing extremely well."

The Eagles are taking a cautious approach with Darby and want to make sure his conditioning is up to speed and he handles practices wel before rushing him back onto the field.

"Obviously with the time off, there's a lot of things that are involved, conditioning No. 1," Pederson said. "That's probably the most important thing. How sore does he get during the week? And by no means do I want to rush him back and just say 'hey, we said this is the week, let's go play.' There's a lot of factors that have to be sort of right, stars have to align for him to be ready to go."

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