For a precious moment or two last Sunday in Denver, an NFL sidelines scene offered all the elements of comic opera.

The Broncos and New Orleans were tied 3-3, early in the fourth quarter. Denver had a third and 10 on the Saint 12, following a penalty against Riley Odoms that set the ball back from the seven.

Craig Morton dropped back, on thir down, and hit Rick Upchurch at the eight in the left flat. Upchurch went for the flag. So did Tom Myers, the Saint defensive back. Myers just missed knocking Upchurch out of bounds at the two and, instead, took the legs out from under Dick Ferguson, the side judge, who was standing out of bounds.

It appeared, to the armchair viewer, that Upchurch had scored . . . but it was close. He might have been out on the one, instead of getting one yard into the end zone. Ferguson, the official, suddenly was in no position to signify what had happened.

The national TV audience was kept in suspense for several several seconds -- particularly those fans who were backing the home team, giving six points -- until, in a performance worthy of Luciano Pavarotti at the Met, Ferguson rose up on his battered knees, threw his arms high into the air (signifying "touchdown") . . . and collasped onto the turf.

A viewer couldn't help but laugh. The cameras had caught every detail of the little drama. But the laughter ended quickly when Ferguson couldn't get to his feet, and a stretcher was brought on to carry him off the field.

Fortunately, X-rays revealed that the official was not seriously injured.

The incident served to focus attention once again on the important role the "zebras" play in the NFL. They have been conspicuous by their absence from headlines this season, after suffering through recent years of criticism for what appeared to be their collective indecision and their inconsistencies.

But this year their overall performance has been excellent. The Ferguson play in Denver was typical in that the official was right on top of the action, in perfect position to make the call -- before being knocked down.

I will go right back to Denver this Sunday, having won there the last two weekends, and take the Broncos in what is rated an even game against New England. This is going to be a struggle, but if Craig Morton can keep from making the critical mistake -- his offensive line in providing improved pass protection -- the Denver defense will do the rest. Steve Grogan figures to have a troubled afternoon, throwing into the Denver linebackers and secondary, and Grogan will have to throw because the Broncos are capable of neutralizing the Patriots' strong running game.

I will risk a mythical $250 on Denver and the same amount of Pittsburgh, Cleveland, Green Bay and Dallas.

The Steelers are healthy, which means Kansas City doesn't belong in the same league, let alone with 10 points. K.C. is one-dimensional of offense, strictly run-oriented. This should make the Pittsburgh defense even more effective than usual.

Cleveland's offense keeps pouring out the points. The Browns are returning home, after victories at St. Louis and Philadelphia, and they should be able to handle Seattle by more than 6 1/2 points. The Seahawks should still be in shock from last week's unbelievable inept effort against Los Angeles.

Green Bay gets the call, giving 2 points at home to Minnesota, simply because the Viking season ended two weeks ao when they merrily lost to Tampa Bay. Bart Starr desperately needs a winning effort and the Pack, finally, is in the right spot to give him one.

Dallas, giving 10 at home Monday night against Philadelphia, is the final selection. The Cowboy offense has been subpar for two straight games. There's no reason for the slump to continue against the frustrated Eagles in what figures to be a high-scoring affair.

In other games this week, Las Vegas lists Washington only 3 1/2 over St. Louis, Miami 7 over Baltimore, New York Jets 6 1/2 over Buffalo, Houston 3 1/2 over Oakland, San Diego 3 1/2 at Cincinnati, Tampa Bay 4 at Detroit, New Orleans 7 1/2 over San Francisco, Chicago 2 over Los Angeles' shaky quarterback situation and the New York Giants 3 over Atlanta.