Hernandez' ankle injury has limited him from cutting as he continues his rehabilitation despite playing in recent weeks. While the Patriots won't fear the Rams without Hernandez, he could prove to be an important loss.
The Rams are not yet power houses of the league, but their defense is substantially better at this point than it was last year. An off-season of investment in their secondary has resulted in the team having some of the better cover cornerbacks in the whole league. Janoris Jenkins and Cortland Finnegan have proven to be very physical and productive cornerbacks who can be trusted in single coverage with opposing receivers.
Jenkins and Finnegan will match up well to Brandon Lloyd and Wes Welker, while the Rams' defensive line talent specializes in getting to the passer. With Lloyd and Welker likely being limited by quality defenders, and the Rams having a front seven that should be capable of limiting Stevan Ridley and company in the running game, the Patriots will focus their offense around Rob Gronkowski.
While that doesn't sound like a bad plan at all, it does also mean that the Rams will be focusing the rest of their coverage his way without worrying about being beaten by the secondary options. If the Rams can limit Gronkowski, that will go a long way to the team upsetting the odds and leaving London with a victory over the Patriots.