It happened near the end of a game against San Diego. Denver quarterback John Elway approached the line of scrimmage, put his hands down to receive the snap and suddenly realized he was standing behind a guard.

"Wrong guy, wrong guy," guard Tom Glassic yelled while he nudged Elway with his leg. Elway, embarrassed, nonchalantly moved over behind the center and began the play.

Elway tries to laugh off the incident. He even giggled at a newspaper cartoon in which the Broncos' center is wearing a sign over his head to help the young quarterback find his way to the football.

"Hey, I'm just a rookie," Elway said the other day with a shrug and a smile.

But the problem is, John Elway is a very special rookie. He received one of the most lavish preseason buildups in history after signing a five-year, $5 million contract that helped escalate the NFL salary structure.

Fair or not, from the time he was portrayed by gushing scouts simply as the best quarterback prospect ever, normal standards have not been used to judge his performance.

But even under usual guidelines, Elway has stumbled. He has been the lowest-rated passer in the NFL most of the year, until Sunday throwing 4 1/2 times as many interceptions (nine) as touchdown passes. He has been benched once by Coach Dan Reeves and is starting now only because Steve DeBerg is hurt.

Since returning to the lineup after DeBerg separated a shoulder, Elway has improved his statistics slightly, and has had flashes of brilliance, especially this past Sunday against Cleveland when he completed 16 of 24 passes for a career-high 284 yards and two touchdowns in a 27-6 victory.

Virtually his every move has been scrutinized and analyzed since the start of training camp. And he has been befuddled by an offense that proved far too complex and sophisticated to learn thoroughly in preseason.

"It hasn't been very enjoyable," he said. "As much as I didn't want to let everything get to me, it has bothered me. I've tried to be myself and not try to live up to all the expectations, but you find yourself pressing."

Dealing with unexpected and sometimes baffling failure this season has became a nightmare for this gifted athlete.

"I've become my worst enemy," he said, shifting uncomfortably on a sofa in the players' lounge. "I've been hard on myself. As I get myself to relax a little, I'll be better."

Even with his buildup, it shouldn't be surprising that he has had problems. One NFL cliche says that quarterbacks need four or five years to develop. But the success of Dan Marino--the 27th pick on the first round--in Miami has added to Elway's burden.

"I can't worry about Dan Marino," Elway said. Left unsaid is the fact Marino joined a Super Bowl team lacking only a top-flight quarterback. Elway joined a franchise coming off a 2-7 season. This year, the injury-plagued Broncos have started a seventh-string tight end, a third-string halfback, a free agent wide receiver. They haven't provided him with much of a supporting cast or a dependable offensive line.

"I think Marino is in a better situation in a lot of ways," said Reeves, a former Cowboys star in his third year as a head coach. "He's got a coach who might be better prepared to bring along a new quarterback than I am in this stage of my career. In retrospect, we probably should have done some things differently with John."

Elway lasted five games. By the time Reeves replaced him, the youngster was shell-shocked. He scrambled at the first hint of pressure. His normally accurate arm betrayed him. He was stiff, at times awkward and uneasy. Against most defenses he was overmatched, a weakness opponents jumped on by blitzing him relentlesly.

His statistics told the story: 38 completions in 83 attempts, a mere 420 yards to accompany five interceptions, 15 sacks and one scoring pass.

"My mind was really cluttered," Elway said. "I was still thinking about where my people were going to be instead of concentrating on what the defense was doing. So I'd forget where all my receivers were. It was like a ball of snow getting worse and worse and growing larger and larger."

Elway had been asked to master an intricate offense in which one play can be run from 90 formations. Reeves would send in a play and Elway would struggle to call the right formation. DeBerg finally began signaling the formation from the sidelines. Still, Elway was confused.

"He wasn't ready to handle everything that we threw at him," Reeves said. "We aren't strong enough to be a basic team, and we were simplifying things too much when he was starting. We had to become multiple again, so we turned to Steve."

DeBerg says the offense was in English for him and in Greek for Elway. As soon as DeBerg took over, a fancier Bronco offense helped the team win four straight games.

"Although no one wants to admit it, there is always something in the back of your mind saying, 'Is everything all right?' " Elway said. "I was losing confidence gradually. I was getting worse. You don't like to get benched but it was the best thing that happened to me.

"We had a complicated offense at Stanford but this one has so many different reads and adjustments, especially on blitzes. Third down in the pros is so different than in college. They throw so much more at you."

During his four weeks on the bench, Elway said, he was able to "learn the offense instead of worrying about the other team's defense." He put in extra study time, and had special sessions with both Reeves and John Hadl, the quarterback coach.

"I'm able to see upfield now," he said. "It's like 5,000 tons was lifted off my shoulders when I was sitting out. I've progressed tremendously since the first game."

Elway's difficulties obviously have raised questions about his future. But Reeves and Hadl, a former San Diego quarterback, remain strongly convinced that Elway will become an outstanding player, given proper time. Elway shakes his head when talking about his future.

"I'm 11 games into my rookie season and this TV guy wants to know if I'm a $5 million flop," he said. "I couldn't believe it. If I had been around five years and this was happening, I'd be concerned. But I'm still a rookie.

"I think I'm a lot stronger mentally because of what has happened," he said. "I have to believe this is a character builder."

His relationship with Reeves has had its rough moments. Against San Diego, the two had a shouting match on the sideline after a couple of botched plays. They've made a pact: both will try to relax more and be more patient with each other.

Now, ready or not, Elway is in the middle of a spirited playoff race. His performance the final two games likely will determine whether Denver, a strong wild card possibility, will enter postseason play for the first time since 1979.

"I've always been convinced that you can't really ever enjoy the good times unless you have some bad times," Elway said. "I think after this, I'm really going to enjoy the good."