Stevie Brown Nat Berhe

Giants free safety Stevie Brown (27) appears to have lost his starting job and it's not rookie Nat Berhe (34) who is expected to replace him.

((Amanda Marzullo | NJ Advance Media for NJ.com))

EAST RUTHERFORD -- When free safety Stevie Brown allowed Texans speedster Damaris Johnson to slip behind him in Sunday's Giants victory, he also may have lost his grip on the starting job. It was the final defensive snap Brown saw in the contest, and may be the last time he's viewed as the starter at that position this year.

Quintin Demps appears set to start for the Giants opposite Antrel Rolle on Thursday night in Washington after taking snaps with the first team during practice. Rookie Nat Berhe finished the game against Houston at free safety and is the Giants' other option, even if coach Tom Coughlin said Brown remains in the safety mix.

"We're looking at all the possibilities. We're just trying to get better," defensive coordinator Perry Fewell said. "It was an internal Giants decision [to make the switch] and I'll just leave it at that."

It's apparent it's a performance-based decision. And now there appears to be a performance-based change in the lineup, with Demps likely being the one to replace Brown.

"It's the NFL. I'm day to day. It's a week to week mindset," Demps said. "It's an opportunity for me to take advantage of it, to do the best for this team that I can be. And just go from there."

Brown appears to have lost his job following a slow start to the season. He missed all of last year with a torn ACL, but is ranked a respectable 30th out of 76 safeties so far this season by Pro Football Focus. Brown has ranked well against the run (+2.8) and poorly against the pass (-2.9).

There was fair warning last week that the Giants weren't thrilled with Brown's play.

"A couple of years ago, we referred to Stevie Brown as kind of a ball-hawking guy in center field when he had that opportunity. He's just not there yet," Coughlin said after their Week 2 loss to Arizona. "He's not back yet to where he was a couple of years ago, and let's hope he gets there."

His performance against Houston was unconvincing. In fact, it may have swayed the Giants in the other direction.

This is a team that likes to have interchangeable players in the deep part of the field that can handle the roles of both free and strong safeties. Demps has the size and speed to do it all, even if he's spent most of his career as a reserve. It's a matter of whether he can put it all together.

The veteran is stepping into a difficult spot. He'll have to keep a close eye on speedy Redskins wide receiver DeSean Jackson. It's a player Demps knows well. Jackson was his road roommate during his first two years in the league with Philadelphia.

"It's obvious. You have to keep the deep ball off you," Demps said. "Everybody in the league knows DeSean is going deep. Everybody knows that."

For that reason, Demps might be playing in Virginia when the ball is snapped from Maryland. His No. 1 job on Thursday night will be making sure none of the Redskins receivers -- particularly Jackson -- get behind him.

"Absolutely. Keep everything in front of you," Demps said. "Deep is the deepest. ... You have to play a little bit deeper with that dude. Four [steps back]. Four. It's DeSean Jackson now. All he does is run. Fast."

Even though Jackson is banged up, the Giants have made sure to plan for him on Thursday night.

"We make a special adjustment [for Jackson]," Fewell said. "You can announce that one. We'll keep our safeties a little bit deeper for that guy."

One of those safeties is expected to be Demps.

Jordan Raanan may be reached at jraanan@nj.com. Follow him on Twitter @JordanRaanan. Find NJ.com Giants on Facebook.