Topping the list of things that can bring a good season to a bad end has to be injuries, and the Patriots are far from immune from this bug that can decide to bite any team at any moment.
It's inevitable, your team is going to suffer through injuries. Some will be long, some short, but there's no doubt they can directly affect the outcomes of plays, drives, games, and even seasons. The Patriots have been the victim of many injuries over the years, but managed to have a rare run of luck when it came to big injuries last season.
They placed 5 players on the injured reserve over the course of their '07 season and as we all know they put up quite the fight. They were lucky not in terms of the amount of injuries, but in terms of who was injured.
The Patriots lost their OLB, Roosevelt Colvin, but managed to tick on without him given their decent depth at that position. Their two headed RB monster was taken away from them when Sammy Morris went down for the season, but it proved to not be a catastrophic loss even with Morris leading the NFL in rushing yards 6 weeks into the season.
The other IR losses included S Mel Mitchell, CB Chad Scott, and TE David Thomas all of whom had no significant role on the team.
This season the threat of injury still looms as strong as ever and there are very specific players that the Patriots cannot afford to lose if they have any shot of getting remotely close to where they were just a few months ago. And here they are:
1. Tom Brady: Really no explanation needed here. If anyone thinks Cassel, Gutierrez, or O'Connell are ready to do what Brady does for this team you're sadly mistaken. If Brady goes down for any significant time the Patriots are in serious trouble.
2. The Offensive Line: The reason the O-Line gets the number two spot of importance in terms of staying healthy is simply because of what's at stake behind them (see 1.). If the O-Line gets roughed up, Brady gets roughed up and we already discussed what that can lead to. The RBs success is also at stake here. With backups in those running holes are going to get a lot smaller and severely limit what our backfield can produce.
3. Adalius Thomas & Mike Vrabel: Losing either of these guys and God forbid both of them really throws a wrench into what seems to finally be a balanced LB rotation. A mix of rookies and veterans inside with Thomas and Vrabel rushing on the outside is one of the best setups the Patriots have had at LB for a long time.
If one of the outside rushers goes down that balance gets upset heavily when someone from the inside is forced outside much like Thomas was forced inside last season.
4. Rodney Harrison: 16th season veteran or not, Harrison is still an integral part of not only the Patriots secondary, but in the entire defense. Now I like Meriweather and Sanders a lot and I have a lot of hope that they can start someday, but I know for a fact that they can't read the field or strike fear into defenders as well as Harrison can. He's a safety, but has a knack to sniff out the run and make huge stops often during games and he's still a shutdown option on some of the very best TEs out there.
5. Stephen Gostkowski: Surprised to see the Kicker here? Okay that's understandable. A question for you though: If he goes down, who kicks all those field goals, extra points, and kickoffs?
While our punter, Hanson, is pretty good I doubt he can do all of that as well as Gostkowski. With the way this offense scores the Kicker is a very active person whether he's got the opportunities to kick field goals or not.
Other obvious notables: Randy Moss, Wes Welker, Laurence Maroney, Ellis Hobbs or really any other substantial starter for that matter.
Like any team the Patriots do have players that they can move on without if they fall to injury, but they also have plenty of vital players that they need in order to achieve what they know that can...if everyone stays healthy of course.