Cornerback DeAngelo Hall and the Redskins’ defense has allowed an NFL-worst 10.2 yards per pass attempt in the first two games of the season.

When asked how he would cover All-Pro wide receiver Calvin Johnson this week, Washington cornerback Josh Wilson had a quick answer.

“Well, I’ve been saying my prayers every day,” Wilson joked.

Wilson and the Redskins’ secondary might need some divine intervention. The unit has allowed opposing passers to complete 73.1 percent of their throws for an average of 10.2 yards an attempt — both NFL-worst figures.

The secondary figured to be Washington’s weakest element this season, and the group has fallen short of the meager expectations heading into another tough challenge Sunday against the pass-happy Detroit Lions and the electric Johnson.

“We’re getting to the point where we just have to do it,” cornerback DeAngelo Hall said. “Talk is cheap.”

The Redskins infused the secondary with youth through the draft, but rookies Bacarri Rambo and David Amerson have been going through serious growing pains.

“You have to be locked in at all times,” Amerson said. “I’ve made some mistakes, but I’ve also had some positives. You have to learn from your mistakes and build on your positives. You have to know what you have to do and you have to tune everything out.”

Amerson has been one of the most visible contributors to a systematic problem for Washington this season: tackling. The Redskins have not been able to wrap anyone up, and that often means receivers and running backs have been running free through the secondary.

“Sometimes it could be a missed tackle. Sometimes it could be a gap responsibility,” Redskins coach Mike Shanahan said. “A lot of different things are involved, but I guarantee you, we’ll work on that this week.”

The secondary woes have also allowed teams to stay on the field en route to building big leads. Washington ranks 22nd in opponent third-down conversions at 44 percent, and that number is worse in the first half.

“Just to be able to get off the field early is important,” Wilson said. “That sets the tone for the whole game.”

The Lions rank seventh in the league in passing and possess one unbelievable wide receiver threat. It all adds up to a daunting task for a unit that has to find a way to prove itself — in a hurry.

“I know the guys in this locker room will compete,” Hall said.