Rapid Reaction: 49ers 24, Eagles 23

PHILADELPHIA -- Some thoughts from the Philadelphia Eagles' absolutely brutal loss to the San Francisco 49ers:

What it means: Huge, huge trouble for an Eagles team that has no reason to consider itself a playoff contender, let alone a Super Bowl contender, after a loss like this. You get a 20-3 lead and your quarterback throws for more than 400 yards against an offense led by Alex Smith? You have to win that game, and you have to win it easily. Instead, the Eagles' defense fell completely apart in the second half and allowed Smith, Frank Gore and Co. to come all the way back and get out of town with a huge upset victory. It's the third straight game the Eagles have lost after leading in the fourth quarter.

At least Vick finished the game: Eagles quarterback Michael Vick, who injured his head two weeks ago and his hand last week, said he was determined to play all four quarters this week, and he did -- brilliantly. Vick threw for 416 yards, rushed for another 75 and looked poised to lead the Eagles on a potential game-winning drive until Jeremy Maclin's costly fumble in the final three minutes. If the Eagles can draw any positive from this awful, awful game, it's that Vick was at least able to play the whole thing.

It's spelled T-A-C-K-L-E: For all of the work they did to improve the defense this offseason, somebody forgot to teach tackling. The Eagles' linebackers and defensive backs consistently go after ball carriers in attempts to make big, bone-jarring, ball-loosening hits, and as a result, big, strong players like Vernon Davis and Gore can bounce off and continue running. It happened last week against the Giants, happened again this week and will continue to happen until the Eagles start stressing defensive fundamentals and execution. Jason Babin was the star of the show with three sacks, but when the Eagles don't get to the passer, they have almost no defense at all.

Too one-dimensional: LeSean McCoy came into the game as the second-leading rusher in the NFL and gained 18 yards on nine carries. That's a game plan flaw, and it's hard to imagine why it happened, especially with the Eagles leading 20-3 at the half. It was important for the Eagles to establish the downfield passing game, and they succeeded in doing that, but a little bit more balance would have helped keep the defense off the field in the second half.

Mistake-prone Eagles: Ronnie Brown trying to throw a pass while being tackled at the goal line? Maclin's fumble? The silly lateral on the punt return when the ball was already in DeSean Jackson's hands? The Eagles play too loose on offense, defense and special teams, almost inviting teams to try to beat them. Often, they look too convinced of their own considerable talent, and they forget the little, important things.

Rookie kicker: Some did ask in the preseason whether it was wise to spend so much money and then leave the field goals to rookie kicker Alex Henery. Not that former Eagle David Akers looked all that good in his return with the Niners, but Henery's late misses were costly.

What's next: The Eagles travel to Buffalo on Sunday to play the 3-1 Bills, who suffered their first loss of the season Sunday in Cincinnati. The Buffalo offense has been much more potent so far this year than San Francisco's, so it's hard to imagine the Eagles' defense containing the Bills on the road.