Must happen/Can't happen at Seattle

SANTA CLARA, Calif. -- Here is a look at what the San Francisco 49ers must do and can't do Sunday at Seattle in the NFC title game:

Must happen: The 49ers have to win the turnover battle. I don’t think they can afford to lose one turnover and they have to force Seattle into, at least, two turnovers. This is going to be a tough-and-tumble game. San Francisco will need some breaks and can’t make silly mistakes.

Can’t happen: The 49ers can’t crumble because of the crowd noise. They simply have to handle it better than they have the last two times they played in Seattle. They were outscored by a total of 71-16 in those two games. The 49ers were really bothered by the noise and were never comfortable on offense.