When one of the best quarterbacks in the National Football League is rated next-to-last at his position after two weeks of the season, people talk. They wonder. They even tell jokes.

One that's been making the rounds at Redskin Park:

Someone called Joe Theismann's house the day after his five-interception performance in Dallas. The phone rang and rang and rang. There was no answer.

Theismann was home, so the story goes. Problem was, he couldn't find the receiver.

Joe Theismann, the quarterback with the low ratings, doesn't mind the joke. In fact, he tells it.

"It could hurt in some instances, but I understand how it's meant," he said, smiling.

Theismann, who has thrown six interceptions and has fumbled away possession twice in two weeks heading into today's 1 p.m. game with Philadelphia at RFK Stadium, started poorly in seasons past.

But because he just turned 36 and the Redskins didn't make the Super Bowl for the first time in three seasons last year and the team easily could be 0-2, not 1-1, he knows there are questions.

"Everybody mumbles, 'What's wrong with Joe?' " Theismann said in an interview this past week. "Well, I don't think anything is wrong with Joe. I'm disappointed by the way things have gone so far, but I know it will change. I will play well."

Theismann finds solace in his history. "I've had horrendous openers," he said.

He has had clunkers, most forgettably a 22-for-48, four-interception day in a 26-10 loss to Dallas, Coach Joe Gibbs' first game in 1981.

The next two season-opening games weren't bad at all, but then, in 1984, he threw two interceptions in a 21-for-36, no-touchdown-pass loss to Miami, 35-17.

Overall, however, no two-game opening stretch in the past five years was as bad as the current one.

He has completed 52.6 percent of his passes and thrown for just 344 yards in two games, not to mention all those turnovers.

Only the first two games of 1981 come close: he completed only 51 percent of his passes then, but did have 599 passing yards.

Then again, the net result -- two losses -- was worse than what's happened this year.

Theismann has been searching for answers, trying to figure out what is to blame.

He says he is in the best shape of his professional life. He will never, ever, lose confidence in his ability to play quarterback, he says. He is the eternal optimist, although, this year, he has become "more of a realist."

He picks out the little things in the first two games because he believes the big picture is worthless. The forced passes, poorly run pass routes, new receivers and a Texas-sized blowout were to blame in Dallas; the three or four surprising safety blitzes were the problem against Houston, he said.

Perhaps the most troubling thing of all, though, was the Redskins' 4-0 preseason. Theismann completed 61.7 percent of his passes, threw for three touchdowns, and had no interceptions.

"For me, things went so well during the exhibition season that you feel like you can do certain things," he said. "You almost get a false sense of confidence."

Theismann said he plans to ask Gibbs if he can play more during next year's preseason.

"I'd like to play more than just one half of an exhibition game. I really think that might help me in an opener. This is hindsight, of course, but I would like to go out and play three quarters in at least one or two of them towards the end, so that you get a feel of going that distance."

Gibbs agrees. "Preseason seems to be misleading for us because I would have thought Joe was sharp," he said.

Gibbs never leaves Theismann's side at times like this. The coach is the quarterback's staunchest defender.

"I gain more respect for him in the bad times than in the good," Gibbs said.

But at least one Redskins official, who did not want to be named, has expressed some disappointment with the way Theismann has played, and even wondered how he will handle the renowned blitzes of the Chicago Bears' defense next Sunday at Soldier Field.

"I've been hit just about every way you can be hit over the course of my career," Theismann said. "I've got 10 other guys working with me on that, and, to me, it's not a concern. We'll do our jobs."

Before the Redskins meet the team that forced them into early winter vacations last year, they must play the Eagles.

It sounds so easy: a team that hasn't scored a touchdown in two losses, a team with a rookie quarterback named Randall Cunningham and without three of its top defenders (linebackers Jerry Robinson and Joel Williams and defensive end Dennis Harrison), all holdouts.

But, were it not for Cunningham, who runs often and has completed just 15 of 41 passes, with five interceptions, Theismann would be at the bottom, Numero 28, in the league's complicated quarterback rating system.

Cunningham's rating is 16.9; Theismann's is 43.2. ("It just finally got above my age," Theismann said. "I'm rolling.")

Seattle's Dave Krieg leads the NFL at 136.9.

Other than the two worst-rated quarterbacks, what does this game offer? Running back George Rogers (sprained lower back) can play, although Gibbs said he will wait until just before the game to decide. It's likely Rogers will not play a lot if the Redskins get ahead early.

Surprisingly, the Eagles defense is quite good, having allowed just four touchdowns this season. It has problems with the running game (are you listening, John Riggins?) and is ranked next-to-last in rushing defense. But it is the league's third-best defense against the pass.

As Redskins free safety Curtis Jordan said, "If you've got a good defense, that keeps you in the game no matter how bad your offense is."

And that offense appears to be pretty bad. Eagles running backs have gained only 75 yards on 30 carries in two games. Cunningham is the leading rusher with 94 yards in 11 carries, mostly unplanned.

The Eagles haven't been good in several years, yet, at home in 1984, they upset the Redskins, 16-10, when rookie Andre Waters returned a third-quarter kickoff 89 yards for a touchdown.

"If our guys overlook them, we'll get beat," Gibbs said.

Theismann, meanwhile, is looking for nothing more than consistency, he said.

"It's most important for me to be the consistent factor on this football team," he said. "Just to know I can go out and make the right decision. Sometimes you think every decision you make is going to result in a completion. Well, it doesn't work that way."

Theismann says he is not pressing. But quarterbacks coach Jerry Rhome said, "Maybe he's trying to do too well."

"I don't know what it is," Theismann said. "But I know this. I will come up with an answer because I want to keep playing."