It's a good argument as to which of the three is most damaging to the team. Gone for the season, it appears, is defensive tackle Antonio Dixon with a torn triceps muscle that requires surgery. Dixon is a space-eating tackle in the middle of a defense that has been gashed by long runs through four games. Gone for an indefinite period of time is right defensive end Trent Cole, a Pro Bowl player who is feared as a pass rusher and who can dominate against the run. He has a strained calf. Also hurt is left offensive tackle Jason Peters, who is battling a strained hamstring.

Waiting is Buffalo with its explosive offense and attacking defense.

Depth is about to be tested. The Eagles have some defensive tackles who have played well -- Cullen Jenkins, Mike Patterson and Trevor Laws -- and they (reportedly, as of 3:53 p.m. Monday) added Derek Landri -- who was with the team in the preseason -- on Monday to replace Dixon. Defensive end isn't so easy. It sounds like Darryl Tapp, who has missed two games with a pectoral injury, could be ready to play against Buffalo. And it also sounds like Juqua Parker, out with a high ankle sprain, has a chance to see some time on the practice field this week.

King Dunlap is in line to replace Peters at left tackle, unless the Eagles think Winston Justice is ready to play again at right tackle and maybe slide Todd Herremans to the left tackle spot for however long Peters is out.

There are options. There are challenges. Adding injury to the insult of blowing a 20-point lead and losing a third consecutive game, the Eagles are in us-against-the-world-mode. Andy Reid's teams have always faced these moments with resolve and wins. What about this team, this collection of players that has really not yet built the necessary chemistry? This is a great test for players and coaches alike.

No doubt, though, the injuries are critical. There may be no more valuable player than Peters, who has played outstanding football at left tackle. Maligned in the last couple of seasons for some penalties, Peters has been better through four games in 2011. He has been more disciplined and dominating, and with his former team waiting on Sunday, there is no place Peters would rather be than in Buffalo with his teammates.

Instead, Dunlap will play left tackle and he will see plenty of Shawne Merriman and the Bills' 3-4 pass rush. Dunlap was at the NovaCare Complex on Monday watching film and preparing to start. He has been there before. He has held down the left side of the line. This is another chance for Dunlap.

Same with the defensive line. Phillip Hunt, Jason Babin, Tapp and Parker have to fill the enormous void created by Cole's injury. It won't be easy. Cole plays with a tremendous motor. He is physical. He is relentless. He requires double teams, and that helps the rest of the defensive line.

So these are tough times. We'll see how tough this team is at this critical juncture of the season ...

• Tough fumble for Jeremy Maclin, the third-year wide receiver who is having a marvelous season. However, he has made two critical fourth-quarter mistakes -- the dropped pass on fourth down in Atlanta and the fumble against San Francisco. Maclin learns from his mistakes. He's a smart kid and a great player. Ball security has been a problem for this team all year. There were a couple of instances against the 49ers when the Eagles escaped without harm, including once when Maclin carried the ball in one hand after a reception and then had the ball pop loose when he was tackled.
• This is a supreme test for the Eagles' defense when they play Buffalo: Buffalo has scored 12 touchdowns in 16 trips into the red zone, with four field goals. Ryan Fitzpatrick is playing brilliantly at quarterback.
• If the Eagles could improve just a little bit in the red zone, the offense would be so awesome. The Eagles are fourth in the NFL in total offense and second in the league in rushing. But in an NFL-most 21 trips into the red zone, the offense has mustered just 80 points with eight touchdowns and eight field goals.
• Defensively, the red zone is a huge problem. The Eagles have allowed eight touchdowns and two field goals in 10 opponents' trips into the red zone.
• A team that used to rank near the top of the NFL in the giveaways/takeaways statistic is now near the bottom. The Eagles are at minus-6 in that category. Buffalo is at plus 6. The teams at the top of the category? Detroit, San Francisco, Baltimore, Buffalo, Green Bay and New England. Check the won/loss records of those teams.
• Special teams could really use a big kickoff return to spark this team. The Eagles' average starting point after kickoffs received is the 19-yard line, ranking them among the bottom three teams in the league.
• Don't go into this game thinking the Eagles are playing a pass-only Buffalo team. Running back Fred Jackson is fourth in the NFL in rushing with 369 yards and is averaging 5.8 yards per carry. LeSean McCoy is fifth in the league with 363 yards, averaging 5.5 yards per attempt.