Against the 49ers the Packers have tried to be physical and I think have gone a lot more with 3-4 against the 49ers than other teams. And Hyde is more physical than Hayward.
I'm hearing a lot of people talking about the TE Vernon Davis and about how good Davis is (and he is) Davis has speed while Hyde has the quickness edge. Yes speed can win that match-up but don't forget there also another match-up for the slot guy. If Davis starts to give him trouble (or maybe even he doesn't) start blitzing Hyde a bit, he's seems like a great coverage LB at times. Capers blitzed Hayward and Hayward got there but just couldn't wrap up, I got a feeling if Hyde gets there he's gonna make sure to wrap up.
So while Davis might be able to beat Hyde deep a couple of times, I got a feeling Hyde can beat an unexpecting blocker to get to the QB a couple times as well.
Also the coaches are probably know this and will keep a Safety over TE Davis (or at least I think they should). They don't have WR Crabtree and while I have much respect for Boldin, he doesn't have Davis's speed.
Hopefully the Packers should be able to shut down the other WR with one CB and focus on Davis, Boldin and the running game.