If the outcomes of December football games are truly need-based, as so often seems to happen in the NFL, then the Eagles are facing a much tougher team tonight in Giants Stadium than the one that loped through a 40-17 loss six weeks ago.

The game will be tougher on paper because it is on the road, of course, but regardless of all the right things the Eagles have said, it will be especially tougher because the Giants need to win much more than the Eagles.

"We're desperate as well," Donovan McNabb argued, "because nothing is set in stone right now."

True enough, but if the Eagles beat the Giants tonight, that will very nearly put a stone marker on New York's season. With a loss to the Eagles, the Giants would be two games back in the division race with three to play, and they would be trailing their two main wild-card rivals, very possibly by the same uphill margin.

If the Giants can pull off a win and Dallas loses at home to San Diego - an outcome that will be known by tonight's 8:20 kickoff - there would be a three-way tie for first place in the NFC East.

That's a huge swing for New York, and the Giants know this game could be their whole season.

"It's very critical," said defensive end Justin Tuck. "We needed to win against Dallas last week, and this week is the same thing, because we're in a position where we're behind both of them."

The Giants have been wildly inconsistent this season, winning their first five games, then losing four in a row in a stretch that included the Nov. 1 loss to the Eagles. Since then, the Giants recovered after a bye week to beat the Falcons in overtime, didn't show up in a disappointing Thanksgiving loss in Denver, and then managed to get past Dallas, 31-24, last week.

Some of their issues have been injury-related, particularly on defense, but the Giants just haven't looked like a team capable of getting itself entirely together this season.

"It's all about consistency. One week we come out and look like an all-American line, and the next week we give up gashing runs," Tuck said about his defensive-line unit. "There have been stretches of plays and games where we're absolutely dominant and stretches where we're absolutely atrocious. We've got to use the momentum from the Dallas win to put these games back to back."

The game against the Eagles wasn't atrocious on the stat sheet. The teams were about even there, but the Giants allowed touchdowns on three big plays - a 41-yard Leonard Weaver run, a 54-yard DeSean Jackson reception, and a 66-yard LeSean McCoy run - and gave up another 13 points when the Eagles had short fields following turnovers.

It was a 40-17 game on the scoreboard, but every game-changing play went in favor of the Eagles. That's certainly to their credit, and they earned it, but it doesn't happen that way very often. The score was 16-7 with five minutes left in the second quarter and ballooned to 30-7 by halftime.

"We were disappointed and I think shocked with a 16-7 score that very quickly was 30 points, to have given up that many points in that fast a time," said coach Tom Coughlin. "We gave up some big plays and certainly that was an issue. We're still a work in progress with regard to that."

The big plays were at least partly due to a lack of pressure brought by the vaunted New York defensive line. McNabb was sacked just twice, threw for three touchdowns, and didn't have an interception, putting together his second highest passer rating (146.7) of the season.

Shaking things up after the Thanksgiving loss to Denver, the Giants benched underperforming defensive end Osi Umenyiora against Dallas, using him only in obvious passing situations. They also elevated Chris Canty to a starting tackle position, benching Fred Robbins, and started Jonathan Goff at a middle linebacker position that has been unsettled since Antonio Pierce was lost to injury.

The changes were only good enough to hold the Cowboys to 24 points and 424 yards of net offense, but the game ended in a win, and the Giants are convincing themselves that could be used as a springboard to safety.

"I thought there were some nice personnel moves that were made there, and the guys played hard and with some energy," Eagles coach Andy Reid said.

That has been a problem for the Giants this season, which is always the sign of a troubled team.

"You can mope around all you want [after a loss], but it means most likely the next team is going to come in and whup your butt, too," Tuck said. "Matching the enthusiasm for being on the football field is the main thing we need to do better."

Teams that need to generate enthusiasm for the game in December usually aren't around long in January. But desperation is a great motivator, and the Giants should have plenty of that. It is what makes tonight's game a difficult proposition for the Eagles, if history is a guide.

The Giants are either going to follow that history or become history themselves.

Contact columnist Bob Ford
at 215-854-5842 or bford@phillynews.com.