The Washington Redskins' latest quarterback decision has been made: Jay Schroeder, not injured Doug Williams, will start today against the slumping Super Bowl champion New York Giants at 4 p.m. at RFK Stadium.

Williams, who has had a sore lower back, practiced yesterday morning at Redskin Park and said he "felt good enough to play," but "not 100 percent."

For that reason, Schroeder, who was benched two weeks ago after a couple bad games, will start against the team that beat him and his teammates three times last season. However, he will not have to face all-pro linebacker Lawrence Taylor, who did not make the trip due to a strained right hamstring, a team spokesman said. Taylor, who has not missed a game in high school, college or professional football, will be replaced by Andy Headen, a fifth-year man from Clemson.

Williams was not activated to the final 45-man roster for the game, which means he will not be in uniform today. Second-year quarterback Mark Rypien, who has spent his entire Redskins career on injured reserve, will become Schroeder's backup today.

"Doug said he's still sore today and he feels like he can hurt himself and the team," Coach Joe Gibbs said yesterday. "He just felt that Jay should take it, so that's what we'll do."

This is the Redskins' sixth change in quarterbacks in 11 games (including the replacement games). And, to hear Williams tell it, there will be a seventh change next week, when he believes he will be 100 percent healthy again.

"We all know Coach Gibbs' rules," Williams said. "If you're the starting quarterback, you don't lose your starting job by injury. So, the way I look at it, I'm still the starting quarterback. It just so happens Jay is filling in now."

So Schroeder, who completed only 70 of 141 passes for 924 yards, two touchdowns and nine interceptions (six in one game) in the Redskins' three losses to the Giants last season, now has an unexpected opportunity to defeat the team that made his life miserable a year ago.

"I think everybody around here is looking forward to playing the Giants," Schroeder said yesterday. "Early in the year, it was the strike teams playing, so that has no bearing on what happens now. They're going to be fired up. They're in a no-lose situation, and we need to put a game together, too. We haven't played that well lately, so we need to get going . . . They beat us three times and it's time for us to turn that around."

If the Redskins win, they will do to the Giants what the Giants did to them last Jan. 11 -- knock them out of the playoffs. A loss to the Redskins (7-3, 4-3 not including replacement games) mathematically eliminates the Giants (3-7, 3-4) from the playoffs. A win by the Redskins puts them three games ahead of Dallas with four games remaining.

But a victory by Washington is by no means a certainty. Look at those nonstrike records; these are two teams who are hovering near .500, one game apart, both in search of their old selves and/or a spark. Right now, neither is the team it was in last season's NFC championship game, nor in either of those 1986 regular season meetings. They were the class of the NFC a year ago. Now, they are struggling.

Yet this game should be quite a show, with many of the major characters in place. Quarterback Phil Simms will return to his starting job for the Giants after missing three games with stretched knee ligaments, and running back Joe Morris probably will start after missing two games with a bruised shoulder.

Nose tackle Jim Burt has a sore back and probably will be replaced by Erik Howard in the starting lineup, but Burt is expected to play. Burt, the massive lineman with the jersey that always looks several sizes too small, was one of the reasons the Redskins decided to build a bigger, bulkier offensive line in the offseason. The Redskins' strategy was to move all-pro guard Russ Grimm to center to replace lighter Jeff Bostic and handle tough guys like Burt. Today, because Grimm is still recovering from a knee injury, Bostic will be back at center against the Giants.

Schroeder and Bostic against Simms, Morris and Burt? Seems like old times, and Gibbs doesn't seem to mind it one bit. Everyone's heard of that old motivator called revenge.

"{Schroeder and Bostic} are the ones who are going to determine how we do {against the Giants}. They're the ones who were playing last year. They have a chance to play hard tomorrow," Gibbs said.

But Gibbs certainly doesn't want any repeats of those three Giants-Redskins games last season. If Morris, who has gained only 280 yards in a disappointing season, is playing at peak efficiency, two of the most important men in the game will be Washington defensive ends Charles Mann and Dexter Manley.

Morris ran roughshod over them a year ago, especially on draws, in Giants-Redskins I. Morris gained 181 yards on 31 carries in the Giants' 27-20 win, and had a three-game total of 82 carries for 330 yards. Mann and Manley were surprised by the double-teaming they saw in that first game and did better in the other two. But Manley, especially, still is preoccupied with quarterback sacks, and must play the run better than he has most of this season for the Redskins to be successful defensively.

Putting the shoe on the other foot, the Redskins running game has not played well against the Giants, nor has it done well against anyone recently. George Rogers, who will start today, gained only 67 yards on 35 carries against New York last season. He managed only 19 yards on 13 rushes against the Los Angeles Rams Monday night. Needless to say, the Redskins are concerned about their ability to run behind a line that does not include Grimm.

Meanwhile, Williams said further examination by specialist Dr. Stephen Blood Friday night found that he has a "locked fifth vertebrae," not a sprained ligament between lumbar vertebrae 3 and 4 as was originally announced. "It's an old injury I probably never knew I had," Williams said.

"I told {Gibbs} I thought it was best if maybe I did not play not because I'm afraid of losing the job, but from a physical standpoint and for the team's sake," Williams said.

Redskins Notes:

The Redskins released former replacement wide receiver Anthony Allen and punt returner Derrick Shepard. Allen set the team record for most receiving yards in a game with 255 against St. Louis, and Shepard returned a punt 73 yards in that game. Neither had been activated in any poststrike games . . . In addition to Rypien, the Redskins activated guard Rick Kehr off injured reserve.