OWINGS MILLS, Md. -- Two weeks ago, rookie third-round pick Terrence Brooks was buried on the depth chart and was already called "a disappointment" on a local sports talk show. Flash forward to Saturday night when Brooks was playing with the first-team defense, making an interception (which was negated by penalty) and running down Robert Griffin III for a sack.

Brooks came to the Ravens with the reputation for being the fastest safety in the draft. The speed by which he has picked up the Ravens' system recently has been just as impressive.

"It was kind of slow for a while," coach John Harbaugh said of Brooks' development. "He just wasn't showing that he understood what he was doing. But I think the light came on two weeks ago football-wise. Now, it's really starting to show up with the way he's playing. That gets me fired up."

Brooks was drafted as a free safety, but he's made his impact as a nickelback. With all of the injuries at cornerback, Brooks has stepped up to cover the slot receiver for the starting defense.

He showed great anticipation in jumping in front of Redskins receiver DeSean Jackson for an interception deep in Ravens' territory, a turnover that was negated by a penalty on Dominique Franks. Brooks then forced the Redskins to settle for a field goal in the red zone when he chased down RG III for a sack.

"I've been able to eliminate the clutter so my attitude is, it's just football," Brooks said. "I just need to do the things I've been doing and get more comfortable. I really feel I've taken the steps to do that."

Asked specifically about the "clutter," Brooks said, "Just thinking too much and not playing. I've learned you can't let things get to you and worry about things. My mindset now is they have to beat me. That's the big thing I'm really harping on."

During offseason workouts and the start of training camp, Brooks was playing safety on the third-team defense.

Then, Harbaugh said he noticed how Brooks seemed more sure about his assignments. Brooks suddenly knew what he was supposed to do and where he was supposed to be.

"For him to jump up the last two weeks the way he has is kind of surprising," Harbaugh said. "It seems like it's usually slower going with that position."

There is still a learning curve for Brooks. In the fourth quarter Saturday, he committed a pass interference penalty and later gave up a touchdown.

With the starters not playing in the preseason finale, Brooks will see a lot of playing time Thursday night in New Orleans.

"If he flies around and does the right thing and plays fast like that," Harbaugh said, "that would be a real good sign for us."