THE 49ERS beat them, and the Eagles knew they let one slip through Riley Cooper's hands in Santa Clara.

The Cardinals squeaked out a win in the desert, and the Eagles came away sure that, once their young receivers became seasoned, the result would be different.

The Packers humiliated them in Wisconsin, and the Eagles could not wait to get another shot.

Then the Seahawks flew east and, with little difficulty, beat the Birds by 10 points.

Since Sunday's loss, the Eagles just haven't seemed right.

Their first three losses all came on the road. All came against teams that were, at least at that moment, playoff contenders, if not favorites.

After the first three losses, the Eagles were a peppy club. Even immediately after the Packers game, the Birds left the frigid field and were steaming in the locker room.

After the Seahawks beat them, the Eagles might have realized just how far they stand from being able to beat complete teams.

The Seahawks were the big brother in this fight, with such an advantage that they just put their hand on the Eagles' forehead, straightened their arm and let the Eagles flail away, futilely.

Impotently.

Against the best team they have faced this season, the Eagles simply could not compare.

The realization of impotence is devastating.

Theirs is the type of impotence that could haunt them for several seasons.

Thirteen games into the season, teams fortified with sufficient talent understand the formula to snuff the Eagles' offense.

First, they stop running back LeSean McCoy by flooding the box.

Then, they dare the Eagles' quarterback to wedge deep passes into small windows in zone coverages. This strategy beset Nick Foles with a rash of incompletions and interceptions. Mark Sanchez, with a weaker arm, generally has declined.

They swarm to hybrid threat Darren Sproles wherever he is. Calls for greater inclusion for Sproles are, obviously, misguided. Sproles averaged more than 8.5 yards per touch in the Eagles' first seven games. He has averaged less than 6 yards per touch since and less than 4 yards per touch in the last three games; no sense in throwing good money after bad.

Sproles understands the futility of telegraphing plays.

"When I'm in the game," Sproles said, "I feel like they feel like I'm getting the ball every time."

They bring plenty of pressure from the right side, where journeyman guard Andrew Gardner and second-year tackle Lane Johnson are targets for confusing extra attackers.

Here's the rub: None of those issues is fixable anytime soon.

The Eagles recognize that.

Inside linebacker Mychal Kendricks, their most promising defensive player, enjoyed perhaps his best performance in three professional seasons Sunday. He was distraught and infuriated after the game.

"If there was anyone who deserved to win that game, it was us. That's how I truly feel," Kendricks said yesterday. "The amount of work we put in, the amount of preparation, dedication - it was just frustrating that things didn't fall the way we wanted them to. I felt like we definitely gave them a great run for their money."

Kendricks thinks the Eagles did all they could . . . and the Eagles lost, 24-14. They were outgained by 301 yards. Seattle held the ball twice as long as the Eagles.

Veteran left tackle Jason Peters, the Eagles' best player, was similarly frustrated. He was even issued a 15-yard penalty for challenging an official.

Neither allowed himself the chance to talk about the Seahawks game Sunday evening.

Both were upset about the officiating, but Super Bowl champions will get benefit of most questionable calls. That, too, is a reality.

Consider, too, that the Eagles have the best special-teams units in football; perhaps the best in team history. Still, it is not enough to place them among the league's elite teams . . . and, unlike offenses and defenses, special-teams units change drastically season to season. The chemistry among this group of specialists might be fleeting.

Granted, this is all observation. Educated observation, but observation nonetheless.

None of these issues should affect the Eagles much as how they play their last three games of the season.

Since Chip Kelly took over last season, the Eagles have shown an almost pathological capacity to compartmentalize.

The Big Picture could be catastrophic, but, to a man, they focus on the next minute . . . even if the next minute is lunch.

They simply were superior on both the offensive and defensive lines on Thanksgiving at Dallas, which hurried injured quarterback Tony Romo, limited the potency of receiver Dez Bryant and allowed them to gang up on running back DeMarco Murray. That should not change when the Cowboys visit Sunday.

The Eagles' trip to Washington next Saturday should be little more than a scrimmage, so dysfunctional is that mess (again).

The season finale at the Giants probably will matter, even if it determines only playoff sites or bye qualifications.

No, it's not the next three games the Eagles need to worry about. It's the next 3 years.

The Birds are constructed with solid pillars: Peters, Kendricks, defensive end Fletcher Cox and his young linemates, safety Malcolm Jenkins, two fine tight ends, a proficient receiving corps and McCoy, a franchise back.

In the short term, only the Cowboys pose any significant threat to their run at division titles.

But without better quarterback play, without better offensive line depth, without an answer when teams sell out against McCoy, and without playmakers in the defensive secondary, the Birds can hope for little more than playoff participation.

Sometimes, being pretty good is more maddening than being downright awful. Being pretty good implies that excellence is only a step or two away.

The realization that excellence is much further off . . . well, that can be downright emasculating.

On Twitter: @inkstainedretch