The Detroit Lions were moving toward what could have been the go-ahead touchdown against the Redskins midway through the second quarter Sunday; for all nearly everybody in RFK Stadium cared, they might have been reading the Congressional Record.

Attention suddenly shifted to a few feet the other side of the water bucket on the sideline, because the Redskins were about to change quarterbacks. That happens about once a decade.

Loyalty is important to Coach Joe Gibbs, as long as it does not intrude too long on winning. So after Jay Schroeder had missed about his eighth sure-fire touchdown pass in two games, Gibbs made the absolutely proper decision in telling Doug Williams to get warm.

The last time Gibbs faced a quarterback in a slump, the New York Giants made the switch -- to Schroeder -- for him. Unlike Joe Theismann, all that was damaged for Schroeder was his ego; he watched his relief pitcher pull the Redskins from a shaky situation to victory.

All that even the most loyal Schroeder followers may have quibbled with Gibbs over was when to yank him. Even Williams figured the switch would not be made before halftime.

On film, Gibbs had seen Schroeder overthrow the swiftest and most open receivers time and again last week against the Eagles; that followed by two games a 15-for-38 effort against the Jets.

Yesterday, Gibbs saw another pass sail over an open receiver (Clint Didier) in the end zone on the Redskins' third series; had he not been decisive, players could have been excused for a least considering mutiny.

Gibbs had been coldly executive about every other position and almost every other Redskin in his eight seasons here. Quarterback is a team's most vital player and Schroeder is vitally critical to the Redskins' future; neither ought to be immune to reality.

The coach used several thousand words to explain the loss of faith in Schroeder, but two of them were all that mattered: "He's inaccurate."

Gibbs also made a wise move by announcing immediately that those two touchdown passes Williams threw in the 20-13 victory had earned him the starter's job next week. Might as well tackle controversy as quickly as possible.

Schroeder was not benched for being mildly and briefly erratic. Sunday was his third grim experience in four games. Gibbs went at least the extra mile with Schroeder, giving him the chance to throw his way out of that 69.2 quarterback rating against a terrible team.

Williams seemed to be caught off guard twice by the man who, as an aide in Tampa Bay, helped him become a first-round NFL draft choice.

The first Gibbs surprise was when he told Williams to get ready this game; the second was naming him the starter against the Rams next game.

"My job is to be a backup," Williams said to the initial wave of reporters at his locker. "Not one time the last week or the week before did he say to be ready to play.

"That's not his style. Going back to last year, you'd have to say he's got more confidence in Jay than the average coach has in his quarterback."

Then the news filtered back to Williams that he would be the regular quarterback, presumably until he throws himself back to the bench. He brightened some and said: "Hey, that's Coach Gibbs' decision."

Never did Williams, in his early years with the bad Buccaneers, endure a Schroeder-like fall.

"Coach {John} McKay stayed with me through thick and thin," Williams said, "but I did throw five interceptions in San Francisco {when Tampa Bay was limping toward the playoffs in 1979}. That was a slump nobody ever had worse."

And how did Williams overcome that awfulness?

"You've got to play," he admitted.

The irony for Williams this season is his being 2-0 in hurry-up relief of Schroeder, with almost no preparation during the week, and 0-1 as the announced starter.

"Maybe they should keep me in the Goose Gossage position," Williams joked. Getting serious, he admitted: "As the backup, you don't have that much to lose. You can throw the dice, be a gambler."

As Schroeder had in relief of Theismann nearly two years ago, Williams quickly went long yesterday. His half-the-field throw toward Gary Clark was short, and Bruce McNorton batted it down.

Williams did get the Redskins a touchdown on his first possession; Clark made a body-twisting catch a few minutes later and made it a second touchdown in Williams' second try.

Was the game this simple?

Of course, it was not. Games bog, as the Redskins discovered in the second half; careers bog, as Williams knows and Schroeder is learning.

"Jay is the future of the Washington Redskins," Williams said. "He has more left in him than I ever had. I'm 32; he's just getting started . . . I haven't been anywhere where most of the time the underdog isn't who the crowd wants."

Absent from the action during practice as Schroeder's backup, Williams still has not wasted his time.

"People may wonder why I go off by myself," he said. "But I'm picking up the signals {relayed from the assistant coach who serves the same function during games}, watching our offense."

Williams said he told Schroeder after the game to "hang in there." Through the media, he told Schroeder to consider "a different perspective and think about it."

That perspective?

"He's the foundation. Just the money they gave him is telling him: 'You're our man.' Coach Gibbs is saying the same thing. The future is in his hands."

It all depends on how one defines future, and Williams has his own unfulfilled ambitions. Schroeder will return as the Redskins' quarterback, he realizes, "but who knows when?"