A cold and simple fact of life in the National Football League this season is that playing against the New England Patriots' defense can leave a quarterback in a state of confusion, if not concussion.

Long after the Patriots had defeated the New York Jets, 26-14, in Saturday's American Conference wild-card game at Giants Stadium, the Jets' physician, Dr. James A. Nicholas, admitted he checked quarterback Ken O'Brien's sensory perceptions and made him count backwards in the locker room at halftime. Then he asked O'Brien what day it was.

"He said 'Sunday,' " Nicholas said.

Such was the wrath of Andre Tippett, New England's all-pro linebacker. Tippett dealt a punishing blow to O'Brien a split second after the quarterback had released the ball on a third-down pass near the end of the second quarter.

The pass was incomplete and O'Brien, the league's top-rated quarterback, didn't get up for several minutes. It was later diagnosed that he had suffered a mild concussion.

On the Jets' first pass play of the third quarter, O'Brien called the wrong formation, which wasn't surprising since he didn't even know what day it was.

"He was like a boxer," Nicholas said. "His reactions were slowing and then in the third quarter the boys in the huddle said he was slowing down even more."

Consequently, with New York trailing, 13-7, with six minutes left in the quarter, O'Brien was yanked and didn't return. Reserve Pat Ryan entered the game and led the Jets to the touchdown that narowed the margin to 23-14, but he led his team no further.

O'Brien was sacked 64 times in 17 games this season (most ever for one quarterback in a season), including 13 times by the Patriots and 5.5 times by Tippett.

Today, the Jets (11-6) held their last team meeting of the season at Hofstra University.

The Patriots (12-5), who have won 10 of their last 12 games, returned to Massachusetts to begin to formulate their game plan for their AFC semifinal matchup with the Raiders (12-4) Sunday in Los Angeles.

The Raiders defeated the Patriots, 35-20, in Foxboro, Mass., Sept. 29.

Following their first playoff victory in 22 years, Patriots linebacker Steve Nelson deadpanned that he was announcing his candidacy for the state senate.

Linebacker Larry McGrew said that if the Patriots reached the Super Bowl, fans in Boston "would go berserk. They've got the Celtics and Bruins up there now. If we won the Super Bowl, Andre Tippett would become the Larry Bird of football," McGrew said.

Beneath the fog of so many emotions, however, this much can be said for sure:

*It seems the Jets simply cannot depend on running back Freeman McNeil once December comes around. Sure, McNeil ran for more than 1,300 yards this season. Yet, as always, injuries slowed him at season's end, when games matter the most.

McNeil gained 41 yards on 16 carries Saturday, a 2.6-yard average. Admittedly, the Patriots are difficult to run against. But McNeil averaged fewer than 3.5 yards per carry in each of the final four games of the season.

Furthermore, in his five seasons with the Jets, McNeil has played in 14 games after Dec. 1 and has rushed for 100 yards just once (102 against Baltimore in 1983). Broken ribs caused him to miss the last game of last season.

Injuries kept McNeil from playing against the Patriots in a 20-13 New England victory early this season and limited him to just five carries in the Jets' 16-13 win over the Patriots Nov. 24.

Nelson said that McNeil's sore left knee didn't seem to bother him greatly on Saturday. "Freeman came at me on one play early. He put a move on me when he was within two yards of me. He didn't get by me, but I just got him by his foot," Nelson said.

*The Patriots' offense scored only one touchdown Saturday, so don't blame the Jets' defense, one of the league's best. The touchdown came on a 36-yard pass from Tony Eason to Stanley Morgan and gave New England a 13-7 lead just before the half.

Cornerback Russell Carter, playing his first game in two months after recently being activated from the injured list, missed a bump at the line and Morgan motored past him.

*The Jets committed four turnovers, three of which led directly to 17 Patriots points. O'Brien underthrew Wesley Walker and safety Fred Marion intercepted at the New England seven-yard line, making a 26-yard return to the 33 late in the half. Just 1:29 later, Eason sent the ball to Morgan for the touchdown that made it 13-7.

On the kickoff following Tony Franklin's 20-yard field goal, which gave the Patriots a 16-7 lead with 6:24 left in the third quarter, linebacker Johnny Rembert forced Jets returner Johnny Hector to fumble at the New York 16.

When a flag dropped and most players stopped moving (it turned out the penalty was against the Jets), Rembert picked up the ball and ran 15 yards for the touchdown that made it 23-7. New England had scored 10 points in 15 seconds.

Finally, Garin Veris, New England's rookie defensive end, intercepted a deflected pass by Ryan at the New York 35 and made a 17-yard return with about five minutes left in the game. This led to the fourth field goal by Franklin, giving the Patriots their final points and giving Franklin a share of a league record held by six other kickers for most field goals in a postseason game.

If you add the 15-yard face-mask penalty assessed to Jets tight end Rocky Klever on a first-quarter punt return by Irving Fryar, which gave the Patriots possession on the New York 44 and set up Franklin's first field goal for the game's first points, then turnovers/penalties cost the Jets 20 points.

McGrew said that because the Patriots and the Jets both are in the AFC's Eastern Division and play each other twice a year, they know each other's tendencies well, "especially the formations."

McGrew said that the Jets' offense did the unexpected on "only about 15 percent of the plays and most of them were pass plays." Of course, this minority total included a second-quarter play fake that suckered McGrew forward as Hector ran by him and caught an 11-yard touchdown pass from O'Brien for a 7-3 Jets lead.

And what of the 22-year playoff victory void? Said McGrew, a fifth-year Patriot, "You hear about those things, but they aren't really relevant to us, to this team."