The guy with the neck so thick he has to turn his whole body to see the sideline takes the ball and starts around end. He drags four defenders to the corner and for a moment looks a little bit like the fellow they called "Hushel" at Georgia.

He's rarely seen these days, the Herschel Walker who came spinning out of Athens, Ga., three years ago with a contract the size of the Meadowlands and a pair of crazy legs that were the envy of the NCAA. The whispers in pro football, even in the U.S. Football League, which once welcomed him as its first major if controversial signee, are that Walker is not what he was.

The New Jersey Generals running back will still get his yards and can still knock a linebacker clear to Manhattan with a jerk of a double-barreled thigh. These days, however, the insistence with which he once ran has dimmed to something that is perhaps journeymanlike, and no one is quite sure where the prodigy stronger than train smoke went.

Knowledgeable observers don't openly criticize Walker's performance in his third year with the Generals. He is leading the league in career rushing with 3,151 yards. But there is a suspicion that these days he lacks the ambition he displayed as a Heisman Trophy winner at Georgia. Since then, he has gone through his controversial dropout from college as a junior and a nagging shoulder injury, and signed a contract worth a reported $5 million over three years that was extended last March to four years worth a reported $6 million.

"I don't think he's playing quite as well as people thought he would," said Dallas Cowboys Vice President Gil Brandt. "Maybe we judge him by different standards. But he obviously hasn't reached that same plateau that an Eric Dickerson is on."

Walker dropped off to 1,339 yards rushing last season after gaining 1,812 his first season. His numbers pale in comparison to those of a couple of young NFL backs, the Los Angeles Rams' Dickerson and Seattle's Curt Warner. Recently he has become almost overshadowed in his own league and on his own team by Doug Flutie, the Generals' rookie quarterback with the arm made of panache, who has taken over the role of star ball carrier.

In a victory over the Los Angeles Express last week, Flutie carried nine times for 97 yards and three touchdowns; Walker carried 19 times for 70 yards. In three games this season, Walker has a total of 186 yards on 49 runs, and in the season opener against Birmingham, he rushed just five times for six yards.

Walker, who will be on display when the Generals meet the Baltimore Stars at Byrd Stadium Sunday (2:30 p.m., ABC-TV), will tell you that nothing has changed but the level of competition. Yet he admits he could be running better.

"I could be running a little tougher," he said. "But I think I can improve a great deal. It's still early . . . In pro ball, you don't see too many backs running over the defense. The athletes are better, and they've become more trained in tackling. People know what I can do. I don't need to prove anything."

Walker's defenders say no one could have lived up to the reputation he carried out of Georgia as the best prospect in many an NCAA season. They also cite the injury, loose ligaments in his right shoulder, which began bothering him his freshman year and nagged him until he underwent an operation in the offseason.

"He certainly hasn't had the impact that people thought he would," said agent Leigh Steinberg, who handles a number of players in both leagues. "He hasn't lived up to his reputation, but that reputation was as the greatest running back of all time. Maybe we measured him by a different yardstick."

One of the most noticeable differences in Walker is that he doesn't seem to steamroll defenses the way he once did. In his glory days as a Bulldog, Walker gained 1,752 yards as a junior in winning the 1982 Heisman Trophy; 1,891 yards as a sophomore, placing second in the Heisman voting, and 1,616 as a freshman in a national championship season, coming in third in the 1980 Heisman balloting. He left mangled linebackers strewn all along the way.

"He ran over people a lot more then," said Express defensive tackle Eddie (Meat Cleaver) Weaver, a former teammate at Georgia. "But then he surprised a lot of people. They really didn't know how good he was like they do now."

"He's not that type of runner," Generals owner Donald Trump said. "He's so smooth, maybe it doesn't look like he's putting out that effort."

Walker's running style underwent a change somewhere along the line, and it may have occurred last season, when he was trying to protect his shoulder from further injury. He has become more of a finesse runner than a power back.

"He has a different style," said Don Klosterman, Express vice president and general manager. "He's light-footed, he doesn't drive. Maybe subconsciously he doesn't want to get that shoulder hurt. He has all the strength, size and speed, and if he gets a crack, he's gone. I dread the day when he plants that foot and lets it go."

The Generals have been turning more often to Maurice Carthon, the fullback who recently signed an agreement to join the New York Giants next fall, in tough-yardage situations.

Coach Walt Michaels has been criticized for his game plans, which some think do not fully utilize Walker's talents. Michaels claims that Walker is better suited for breakaway situations than short yardage, despite his 222 pounds, and the Generals are using him more often in pass receiving situations. Carthon has outgained Walker this season with fewer carries, 194 yards on 36 attempts.

"Carthon is a fullback and that's the way we like to use him," Michaels said. "He gets a lot of yards that way and we try to give him the ball in those situations. We try to use Herschel when he can go all the way."

Walker ignores speculation on his decline, and claims his shoulder is fully recovered since the offseason operation. He stands by his accomplishments, but with a complacency that might be telling.

"I think I'm satisfied," he said. "I'm one of the leaders in rushing in the league overall. There's nothing disappointing in that. I've matured a great deal as an athlete and an individual. I don't think anyone could say I'm in a bad position. I'm in a very good position."