ASHBURN -- The Redskins' defense would have faced questions anyway. It allowed too many big plays against St. Louis. There's a string of high-scoring games in its recent past, and it was supposed to be better.

Then the questions got tougher when defensive end Adam Carriker and linebacker Brian Orakpo were lost for the season. Much tougher. Now the Redskins must replace a solid defensive lineman, whom one NFL source called their best role player. And they must replace one of the most talented players on the roster.

And still get better.

Redskins receiver Pierre Garcon, who missed the St. Louis game, still hasn't practiced in full this week. And coach Mike Shanahan did not sound optimistic about his chances for playing in the home opener Sunday vs. Cincinnati. "He's working extremely hard, but it's still sore," Shanahan said. "That's why he's not taking all the reps. ... You just kind of keep your fingers crossed, but it's nagging him a little bit more than I was hoping it would." Garcon bruised his right foot in the season opener at New Orleans and was limited to eight plays. "Hopefully it gets well," Shanahan said.
» Cornerback Josh Wilson (concussion) and safety Brandon Meriweather (knee) both were limited as well. Meriweather still had his left knee taped.
One improvement in Leonard Hankerson's game? Blocking. He had several key blocks against St. Louis, including on both of Alfred Morris' long runs (totaling 56 yards). "He has size. He's not like Niles Paul out there where he's a trained killer," Redskins offensive coordinator Kyle Shanahan said. "He won't turn anything down. He understands the run game and who people are and takes the right angles and gets on people."

"When you lose somebody, you'd like to have everyone step up," defensive coordinator Jim Haslett said.

That's what it will take for the defense to overcome the loss of two key players. The Redskins need to hope a second-year end in Jarvis Jenkins, who missed all of his rookie year, matures quickly. He admits he's still making rookie mistakes.

Carriker had started 34 games in the 3-4 defense. Jenkins has played in two games -- and mostly in the nickel package, which resembles more of the four-man front he played in college. He's still learning how to occupy two blockers, something Carriker did well.

"I just have to know the blocking schemes," Jenkins said. "I'm getting to know the calls the coaches give me. When I get a pass rush, I have to rely on how the line shifts and basically just grow as a pass rusher. It comes with experience. As I go along in my career I'll notice it even quicker, so I'll study more film and know what I'm getting."

The Redskins will try to replace Orakpo with two players who have spent five years as backups. Rob Jackson has one career sack in 28 games, while Chris Wilson has six in 66 games (but one in his last two years combined). Neither has started a game.

"I have to work on some coverage skills," Jackson said. "As far as stopping the run and rushing the passer, I have that down pat."

Wilson's reputation is that of a pass rusher only. The ability to stop the run and play in coverage, a must for a 3-4 outside linebacker, is still developing.

"That comes with repetition and experience," Wilson said. "I'll fine-tune my techniques and get the job done."

The burden falls on the entire defense but a few players in particular. Linebacker London Fletcher's ability to line up defenders in the right place will be crucial, especially in coverage. End Stephen Bowen, who meshed well with Orakpo as a rusher, will need to learn how Wilson and Jackson rush.

"I know his strengths, and he knows what I like to do," Bowen said. "It becomes second nature."

But that takes time to occur.

Then there's Ryan Kerrigan. The Redskins wanted to have Kerrigan and Orakpo switch sides quite a bit this season, as they did in the opener. But minus Orakpo vs. the Rams, Kerrigan lined up only one time on the right side.

And Kerrigan likely will encounter more attention from offenses until the others prove themselves.

"They were chipping [Orakpo] a lot last week at New Orleans, sending a tight end in motion to his side," Kerrigan said. "He definitely [drew] a lot of attention and makes it easier on everyone else."

The replacements -- players, not refs -- hope that doesn't change.

"Our motto is no drop-off," Wilson said. "We plan on living up to that."