Often a certain joyous tension will surround a promising sporting event. The sense that an unknown will soon be resolved provides the keen edge that only the most dramatic moments afford. But here in the desert, where Alexis Arguello will attempt Friday night to avenge his loss 10 months ago to Aaron Pryor, there is an unmistakably ominous, even deathly, feeling.

When they fought last Nov. 12 in Miami's Orange Bowl, Arguello was favored to take Pryor's WBA junior welterweight title. For nearly an hour the two men slugged relentlessly. Arguello forsook his more precise style and tried matching punches with Pryor.

With the judges scoring the fight about even through the 13th round, Pryor hit Arguello with a vicious right early in the 14th. That set off a tremendous magazine and all at ringside could hear the report of glove against flesh as Pryor battered Arguello against the ropes. The referee finally ended it. Arguello sank to the canvas and lay there for nearly five minutes.

The next day doctors pronounced Arguello's health satisfactory, but boxing suffered a hideous blow, the death of South Korean fighter Duk Koo Kim after a fight with Ray (Boom Boom) Mancini. That bout took place here at Caesars Palace, the site of Friday's fight (closed circuit TV at Capital Centre at 10:30 p.m.).

This week, as Arguello and Pryor prepared for their rematch, another fighter died, and with that death came another storm of criticism of the sport's brutality. Kiko Bejines died from blows to the head suffered in a WBC bantamweight title bout with Albert Davila.

Arguello is 31, three years older than the champion. He has three titles and 83 professional bouts behind him, including wins over tough fighters such as Mancini, Alfredo Escalera, Cornelius Boza-Edwards, Bobby Chacon and Rafael (Bazooka) Limon. Arguello would become the first fighter in history to hold titles in four weight divisions if he is able to marshal enough strength and endurance to beat Pryor. The question is: can he forget the past and all the talk about brutality?

At a press conference, Pryor's new trainer, Emmanuel Steward, said, "Alexis took one of the most vicious beatings in that fight; he can't forget that. It will always be in the back of his mind. Any time a man takes those solid blows to the brain like he did, he will never be the same.

"When he gets hit like that the first time Friday night, he's going to rememeber. The closet door where he has stored the previous fight and all those punches he took will open."

Pryor's previous trainer, Panama Lewis, was banned from boxing by the New York State Athletic Commission, a decision upheld by Nevada officials. After the first Pryor-Arguello fight, Arguello's handlers accused Lewis of illegally "refreshing" Pryor with swigs of a mysterious liquid concoction from a black bottle.

Arguello, who was born in Nicaragua and now lives in Florida, vows that this will be his last fight, win or lose. Pryor makes the same claim, but he is likely to find a lucrative fight with Mancini enticing. Arguello's determination to win this time is clear, but comes without the sort of braggadocio that has become the tiresome norm since the Muhammad Ali era. Having lost once before to Pryor, the possibility of a repeat performance haunts him.

"What (Pryor) did to me will be in my mind forever," Arguello told the Los Angeles Times. "I can lose again. I can lose. I am not a magician or Superman. That is fantasy."

Arguello's apprehension is well-founded if the Christmas-tree-like betting board on the casino floor of Caesars Palace can be taken as an accurate reflection of boxing opinion. Pryor, who has won all 33 of his professional fights, 31 by knockout, is an 11-5 favorite to retain his championship against Arguello (78-5).

Arguello's frustration after his loss to Pryor was so accute that he blamed Eddie Futch for "overtraining" him. Although he apologized for his remarks, Arguello now retains Lupe Sanchez as his trainer. The task of the Arguello camp is huge. With such a brutal beating behind him, with such an experienced champion before him and with such awful doubts shrouding him, Arguello faces a dark unknown when he steps into the ring on what he promises is the final night of his boxing career.

"I'm not worried because my family is taken care of. Still, sometimes you wonder if it could be your turn," he said.

"I tell you this. I will put the last drop of my heart in this fight."