One night recently, Gene Upshaw, the 6-foot-5, 255-pound president of the National Football League Players Association, approached a newsstand, gazed down at its proprietor, and said, basso profundo, "Do you have that magazine with me on the cover?"

The cover with No. 63 in picket sign and pads, muscles bulging, veins popping, and just a touch of sweat on his brow. Just enough to show he had not yet begun to fight. "Generally speaking, you know when you've met Gene Upshaw," said Ed Garvey, executive director of the NFLPA.

In 16 seasons with the Oakland/Los Angeles Raiders, Upshaw has never been an invisible man. It is no accident that he has become an increasingly visible (and vocal) symbol of union strength, muscular solidarity. "It's a player's union," said Garvey. "It's much more effective when players do the speaking."

"I say whatever I have to say," Upshaw said. "My physical stature says the rest."

He weighed 13 pounds when he entered the world, 120 when he entered high school, 190 when he entered Texas A&I University and 235 three months later. He does not think of himself as either a "big guy" or an intimidating one. Just an effective one. "If I was a little, small guy, I couldn't be an effective (union) leader," he said.

When the players went on strike in 1974, Upshaw went to the Dallas Cowboys' training camp in Thousand Oaks, Calif., to address a group of rookies, free agents "and scabs," Garvey said.

"I asked if they had questions," Upshaw said. No one raised a hand.

There was a league attorney present. "He (Upshaw) told the lawyer, 'Why don't you come sit on the table? And don't you turn around. I don't want you to intimidate them,' " Garvey said.

"A lot of hands went up," Upshaw said.

"Then he said, 'Do you want to know what a professional football player looks like?' " Garvey said. " 'This is what a professional football player looks like,' pointing to himself. 'As I look around this room, I don't see too many. If you think you guys are going to play in this league, you got another guess coming.' "

"I wanted them to know, 'They're just using you to break the strike,' " Upshaw said.

Upshaw says he isn't the radical some may think: "Maybe it's because I'm big and I'm black and I feel very strongly about a position I've taken. So you get classified as militant."

"I've always been a very conservative person," he says.

Upshaw has toiled in the trenches long enough to know that political infighting is no kinder than that on the football field. League officials, including NFL Commissioner Pete Rozelle, have raised questions about his relationship to Al Davis, the owner of the Raiders.

According to Joe Brown, NFL director of information, Upshaw is "an adviser or employe of Al Davis in the Eastmont shopping mall (in Oakland)." He questioned "whether Gene Upshaw can speak with objectivity as union president on matters affecting Al Davis," specifically the pending antitrust legislation the union opposes.

Upshaw says at one time Davis, a limited partner in the mall, asked him to do some community relations work--signing autographs and shaking hands--but that he was never paid for it. "They seem to be saying, 'I control Garvey and Al Davis controls Gene Upshaw because I work for him,' " Upshaw said. "Rozelle forgets who he works for. He works for Al Davis. Davis doesn't work for Rozelle."

Michael Lapin, the general and managing partner of the mall, says Upshaw has never been part owner or been on its payroll. Lapin says he has allowed Upshaw to occupy some office space for free as a matter of friendship.

Davis said, "Upshaw's totally clean. They'll impugn anyone's integrity to get their way."

Upshaw grew up in Texas, "a right-to-work state," wanting to be a baseball player. "I never grew up around unions. I never knew what they were," he said. "When I came to California (as the first-round draft choice of the Raiders in 1967), I saw picket lines and strikes."

Upshaw remembers one day about 1970 when "Al Davis called me in and said, 'It's about time you take a leadership role on the football team.' Probably that was the catalyst for things going on within me."

Upshaw became union president in January 1980 and was reelected last February. He is actively involved in community affairs and local Democratic politics. He was appointed to the board of governors of the California Community Colleges (1979-81) by Gov. Jerry Brown.

The transformation of the all-pro guard into the all-pro pol is in progress. At age 37, after 16 durable years in the NFL (he missed only one game in 15 years), six years in the Pro Bowl (a shoo-in for the Hall of Fame) and two Super Bowl rings, he says, "I'm really considering doing something else."

He decided 12 years ago that someday he would run for political office. "That's what I'm going to do," he said. "I'll definitely start either on the congressional level or on the statewide level . . . One thing about politics: it's like an airport. If you sit around long enough, you'll get the one you want."

Upshaw's loyalty to Davis, his testimony on Davis' behalf during the first trial in Los Angeles, could have political consequences. Mary Warren, the Alameda County Democratic chairman, said, "Political strategists in Oakland have indicated they would want to reevaluate his political potential in light of his support of the move of the Raiders to Los Angeles."

Upshaw sees his future intertwined with that large group of people "who couldn't have a voice, don't have a vote." He wants to take some of the congressmen "out of their limousines and plush offices" and show them the ghetto. "You gotta feel the dirt under your hands," he says. "You've got to sit at a table with mice."

He refuses to be pessimistic about race relations, about the plight of the poor, "until I get in Congress."

He will be optimistic until he sees it can't be done. "If I'm involved in the process, I'll get it done," he said.

The dome of the Capitol loomed above him. His next office? "Where's that house with all the gates?" he asked, smiling. "You know. The white one."