EAST RUTHERFORD, N.J. -- The New York Giants signed Quintin Demps primarily to be a kick returner, but he's a safety too, and he knows the most important thing about playing the position.

"You've got to be deeper than the deepest," Demps said Tuesday. "Deeper than the deepest, that's what it's all about."

Stevie Brown did not heed this lesson Sunday, when he took a shallow route on a Ryan Fitzpatrick pass to Damaris Johnson and got burned for a 44-yard touchdown in the third quarter of the Giants' victory over Houston. It was the third straight rough game for Brown, who's been slow to work his way back following the ACL surgery that cost him all of 2013, and the Giants have had enough. Brown was benched for the remainder of that game for rookie Nat Berhe. And on Tuesday, Demps was taking Brown's first-team reps at safety.

"It's an opportunity for me," Demps said. "So I just take advantage of the chance to be the best I can be for this team and go from there."

It's not the easiest week to take over as a Giants safety. Tuesday was their only full practice of the week, since they're headed to Washington for the Thursday night game. Washington's offense features two of the best receivers in the game in Pierre Garcon and DeSean Jackson, and Jackson's rare speed is one of the toughest challenges a secondary faces all season.

"You've got to play a little bit deeper with that dude," said Demps, who roomed with Jackson when both were rookies with the Philadelphia Eagles in 2008.

So, if you normally back up two steps, then against Jackson it should be three?

"Four," Demps said. "It's DeSean Jackson, man. All he does is run."

Giants cornerback Dominique Rodgers-Cromartie is also a former teammate of Jackson's, having played for the Eagles in 2011 and 2012, so he's practiced against him, too. The two are close friends, and Jackson offered Rodgers-Cromartie a compliment Tuesday when asked if his former teammate had the speed to cover him.

"DRC is fast," Jackson said. He's one of the ones that can."

Rodgers-Cromartie is likely to draw that assignment, though Garcon, who led the league in catches last year, is no picnic on the other side. Garcon wins with his size and physicality and has shown the ability to catch the ball in short range and take it the distance. But like most of the receivers in the league, he doesn't have Jackson's speed, and so he's the more desirable assignment by default.

"I'd rather face the bigger guys," Rodgers-Cromartie said. "Those shorter, quicker guys are much more difficult."

It's basically a coincidence that the Giants are making a change at safety on the week they face Washington. Brown had a bad first game, running into Rodgers-Cromartie on Calvin Johnson's long touchdown in Detroit. And after the loss to Arizona, Giants coach Tom Coughlin said Brown still didn't look like the ballhawking player he was in 2012, when he got eight interceptions. After another rough game Sunday, it was time for a change.

Demps is a very fast safety (hence his kick-return responsibilities), but he said he believes he can play strong or free safety and allow the Giants to switch off him and Antrel Rolle as is their preference.

"I feel like I'm interchangeable," Demps said.

His mission Thursday is to make the Giants' decision to change their starting lineup look good. And, of course, to be deeper than the deepest.