Defensive end Fred Stokes reported to Redskin Park yesterday morning with a left shoulder that was as sore as the Washington Redskins feared it might be after watching it pop out of place several times during Sunday's season-opening 31-0 victory over Phoenix.

So even before turning their VCRs to the San Francisco 49ers, the Redskins began the business of shopping for defensive line help and guessing how much Stokes will be able to play.

General Manager Charley Casserly telephoned Alonzo Mitz, who was let go in last week's final roster cut, and told him to be prepared to fly to Washington in time for Wednesday's practice.

Casserly said no decision will be made until today, but last night it looked as if Mitz would return as a seventh defensive lineman and pass-rushing specialist.

The Redskins knew that going with only six linemen was a gamble in any year, but especially with Stokes having not played in a preseason game, and until Sunday, having not been hit hard.

They'd hoped they could get through the first few weeks with six healthy linemen -- until injured Jumpy Geathers returns in November.

"We're going to see how Fred works through this," Coach Joe Gibbs said. "We're getting a little nervous about {carrying six linemen}, and we've talked about that some today."

Trainer Bubba Tyer said Stokes still might be able to finish the season without surgery. However, he probably won't practice this week and his availability may not be known until game time.

That leaves the Redskins thin. The starting front of Charles Mann, Tracy Rocker, Darryl Grant and Markus Koch had a solid day against the Cardinals, but their only backups were Stokes and newcomer Tim Johnson, who is still playing his way into shape.

Mitz, signed by the Redskins last summer after being released by Seattle, will at least provide insurance if Stokes has more problems.

For now, the Redskins don't really know what to think of Stokes. Tyer watched tapes of when the shoulder popped out on Sunday, and the first time "there was no contact," he said. "He swung his arms around looking for the fumble, then pulled up. That was it."

An earlier test showed no structural damage to the shoulder, and doctors have assured the Redskins that even if the shoulder continues to pop out, Stokes won't suffer permanent damage.

"We're going to keep working on protecting him and getting him stronger," Tyer said.

Stokes is wearing a harness and Tyer said it could be tightened so the shoulder would never pop out. "But he probably couldn't use his left arm either," Tyer said. "What we have to do is find some happy medium."

The news on Stokes is one of the few negatives to come out of the Phoenix game. The Redskins forced the young Cardinals into five turnovers, got three touchdown passes from Mark Rypien and showed off enough glitzy offensive formations to worry the 49ers at least a little bit this week.

Gibbs said the defending Super Bowl champions would be a tougher test than the Cardinals, but refused to apologize for the victory, saying it was more impressive than people might think.

"The Cardinals are going to make a run yet this season," he said. "We'll see about that and some people might be wrong. They're going through the first-year things we went through. But they've got some good plays. Their defense had a great effort. They just made a lot of mistakes. It was one game for us, but it was good to get it. Now, we get to find out what we look like against the best team in football."

But he acknowledged the 49ers would be different. "Everyone knows that," he said. "We know what's in front of us. It'll take a great week of preparation and a great game on our part."

Gibbs offered further explanation for a new offensive formation in which he sends in three tight ends, then deploys them as wide receivers. It was in this formation that wideout Ricky Sanders -- lined up in the slot -- got isolated with a linebacker in the first quarter and caught a 37-yard touchdown pass.

"When teams see you send in three tight ends, they normally send in bigger people," Gibbs said. "We've experimented with doing some different things with those people."

He can afford to because Don Warren, Jimmie Johnson and Ron Middleton all can catch the ball and defenses no longer can answer what appears to be running-game substitutions with a running-game defense.

Gibbs said it might be different against the 49ers "because they don't substitute as much as some others. They've got great athletes out there and they just try to match up with you."

He ended up calling for passes on 16 of the first 20 snaps, but said that was only because the Cardinals were "in a defense that we wanted to get them out of. They'd were showing us a different look to stop the run and we wanted to see how they'd react in different situations."

It was interesting to see how Rypien reacted. He missed high and low on several plays, but connected on a lot of big ones: His first three completions were all on third and long and all kept the first drive alive.

But when Washington took a 7-0 lead on its second possession, he got hot, hitting Sanders for 8 yards, Art Monk for 7, Sanders for 19 and 37 (the touchdown).

He finished with numbers that were less than dazzling -- 17 of 31 for 240 yards -- against a young team. However, he didn't throw an interception and made enough big plays that the game was virtually never in doubt.

"He played a good solid game," Gibbs said. "There were some things he missed, but they were showing us some defensive looks we weren't prepared for. We had to switch the game plan in some areas."

Gibbs also couldn't say enough good things about a defense that was almost perfect. Martin Mayhew intercepted two passes, Darrell Green got one and Alvin Walton returned one 57 yards for a touchdown. Wilber Marshall also forced a fumble, and the Cardinals had only one long drive, that for 70 yards in the fourth quarter after the game had long since been decided.

"We played a lot of young guys last year down the stretch," Marshall said, "and you see the difference it makes for them to have played together and been through things. We're starting to get a feel for each other and there's no substitute for that."

But next week -- on the road -- will be different.

"They have a style that's unique," Gibbs said of the 49ers. "Not everyone can do the things they can, but they have unique people. They play mostly zones on defense, but they do it well. {Joe Montana} is mobile and doesn't make many mistakes. It's what you'd expect from a team with that kind of record."