SONNY JURGENSEN is not the Redskins quarterback anymore.And no one can sit in RFK Stadium on a summer's afternoon and expect the Washington Senators to take the field these days either. All that is bad enough, but now Wes Unseld is retiring. This is just too much. The Bullets cannot be the Bullets without Mr. Unseld. At best, they can be the Bullets After Mr. Unseld. As the team's captain and starting center, Mr. Unseld is the personification of professional basketball in this basketball-crazy town. Even so, it is characteristic that this man-team who brought the metropolitan area its first national athletic championship in over 36 years never became a great public hero, unlike the smiling, joval Jurgensen.

The Bullets' captain is a private hero. He doesn't make the social scene. He doesn't make spectacular plays; he is a center, but he almost never does the basketball play all America loves, the dunk. What he did do was lead the Bullets to the playoffs 12 straight times before this year; he took the team to the championship finals four times and won the top prize once. Yet for all that, Wes Unseld has never been a regular on the league's all-star team. He is not nationally famous. No, Mr. Unseld's athletic performances were a pleasure to be savored by people lucky enough to be in Washington or Baltimore during his career. He was a steady friend, an athlete who consistently gave it his all. And in an era of zillion-dollar contracts negotiated for athletes by agents, Wes Unseld, the athlete draped in sweat and straining to win, never draped himself in jewels and egotism. He did not have an agent. In a straightforward, man-to-man way, he personally talked about money with the owner and shook hands to fix the deal.

To people who don't play or follow sports, it may not be significant that Wes Unseld is so strong in character. But in its ideals, American athletic virtue has never had so much to do with superstars, agents and lack of loyalty as it has in the past decade. In much the same way that Wes Unseld stands fierce, unsmiling, rock-like and unemotional, holding down the middle of the Bullets defense or setting picks on offense, he stands unmoving from the center of those old athletic virtues. In all his years in professional sports, he played for the same team, played with little hurts and played with all his heart. No boorish sulking, no demands for more and more money, no hot-dogging for attention.

The Bullets should retire Wes Unseld's uniform, No. 41, and hoist it up to the rafters with the championship banner. It would be an act of class for a class performer.