1) Problems against the run
New England has done OK against the run, but they still rank as one of the bottom teams in the league against the run (19th overall) giving up 117 yards per game. If the Patriots can't make the Rams one-dimensional, it will cause problems for the Patriots secondary, which has been victimized by teams all season. The Rams will be without Steven Jackson making it much harder for them to churn up big chunks of yardage, but they still have Michael Pittman who can gain yardage on his own.
Without Rodney Harrison to fill in the box, James Sanders and Brandon Meriweather will need to be cognizant of the run. If not, playing deep or playing the pass could open up huge lanes for Pittman and the Rams to run through.
2) Bulger Can Still Throw
Two weeks ago, the San Diego Chargers burned the Patriots repeatedly using deep passes. Philip Rivers connected on bombs almost at will, burning Deltha O'Neal twice on huge plays. New England has given up 5 plays over 40 yards (T-4th worst overall) and could give up more against Bulger who has found a new favorite target in Donnie Avery. The Rams passing attack may be limited averaging just 252 yards per game (31st overall), but Bulger still has 4 passes for over 40 yards (T-6th best overall). Without Rodney Harrison in the deep secondary, Meriweather and Sanders will need to make the coverage calls that's a potential for disaster if they don't get it right.
3) Third Down Defense a Problem
New England has given up far too many long drives by opponents because they continue to struggle on third down defense. New England has allowed opponents to convert nearly 41% of their third down attempts (T-9th worst overall). The Rams need only use their running attack to make third downs manageable and they can sustain drives. Sustained drives lead to points, something which could be an issue for the Patriots. Even if St. Louis is limited to field goals, expect their offense to be capable of scoring against a susceptible Patriots defense
4) Cassel Can Still Struggle
Matt Cassel turned in a solid performance last week against the Denver Broncos, managing a career-high passer rating of 136.3 by completing 18 of 24 passes (75 percent) for 185 yards and 3 TDs. Unfortunately he was able to do that because the Patriots running game was on fire. Without a solid rushing attack the pressure will be on Cassel to convert third downs and sustain drives. That type of pressure doesn't favor the Patriots. Cassel has been sacked 25 times, 2nd worst in the league behind only JT O'Sullivan for the lowly 49ers. The Rams managed 3 sacks last week against the Cowboys and 4 the week before against the Redskins.giving the team 14 on the year (13th overall). By comparison, the higher ranked Patriots defense has only 10 on the season.
5) No Backs To Run The Ball
Without Sammy Morris or LaMont Jordan or Laurence Maroney, the Patriots must find a way to establish the run. New England no longer has the luxury of being able to rely on the powerful legs of their top two runners. Kevin Faulk could fill in for most of the third down situations, but it will be up to BenJarvus Green-Ellis to keep the Rams defense honest. Green-Ellis saw extensive action last week in the second half with Morris sidelined by injury. If he can continue his average, that will bode well for New England. Green-Ellis has carried 13 times for 65 yards (5.0 avg.) with 5 carries for a first down.
The problem is if New England must change their offensive game plan without Morris or Jordan, the Rams will be able to key on Green-Ellis and Faulk. Heath Evans isn't really a threat to run the ball, so the Rams will be able to focus on a limited game plan from New England.