SANTA CLARA -- Strong safety Donte Whitner, who played against New England frequently while with the Buffalo Bills, knows the perils of trying to match wits with Bill Belichick and Tom Brady.
During one forgettable matchup, the Bills spent all week concocting a look in which they'd drop nine defenders into pass coverage, figuring the nutty scheme would throw Brady for a loop.
"Yeah, we tried that one time," Whitner said, ruing the day. "We felt like it was going to work all week. And then we went out there, rushed two, dropped nine -- and Brady threw a 70-yard touchdown. So it didn't work too well."
It wasn't quite as bad as Whitner remembered: It was merely a 43-yard touchdown pass (as part of a Patriots' 56-10 victory). But the memory demonstrates the daunting task the 49ers are up against Sunday night: Make a mistake and the Patriots will make you pay. Play merely well instead of excellent and the Patriots will make you pay.
"If you slack in any given area, you know Tom Brady will eat it up," defensive lineman Ricky Jean Francois said.
Luckily for Whitner, these 49ers (9-3-1) are clearly better equipped to take on the challenge of the red-hot Patriots (10-3) at ice-cold Gillette Stadium. When the 49ers hopped on the plane Friday, they packed the league's top scoring defense (14.2 points per game), second-ranked passing defense (184.7) and leading sack artist (Aldon Smith, 191/2).
At best: This prime-time showdown
At worst: "It's a measuring stick for all of us," cornerback Tarell Brown said. "I think we'll all be tested and challenged throughout the game. And that's the good thing about it."
Here are the matchups that could decide the much-hyped showdown:
Aldon Smith vs. Nate Solder
While Smith was chatting with Boston-area writers this week, a reporter mentioned there are those who would argue that sacks are overrated. The 49ers linebacker stopped him cold. "I don't know who said that," Smith said, "but I think they're wrong."
The Patriots ought to know. Their ability to dominate is almost directly correlated to their ability to keep Brady upright. Consider that in the six games New England has won by more than 10 points, Brady has been sacked a total of three times.
In New England's other seven games, the Patriots are 4-3 and Brady has been sacked 17 times.
That's what makes the matchup between Smith and the Patriots left tackle so pivotal. It's also a rematch of a meeting Smith and Solder had as college players, when Smith smoked the Colorado lineman for three sacks in Missouri's 36-17 win.
"I haven't watched that game in a long time," Smith said this week. "That was a long time ago. I was able to get past him and create pressure back there ... I'm sure (Solder) has improved. He's made it this far. He's starting."
Smith has at least one sack in seven consecutive games and 14 sacks over his past six games.
Vince Wilfork vs. Mike Iupati
Chess pieces don't come much bigger than Wilfork. The Patriots list the Pro Bowl defensive tackle at 325 pounds, but 49ers coach Jim Harbaugh and Iupati described him as closer to 350-plus.
Whatever he weighs, Wilfork's freakish blend of power and speed create matchup nightmares for opponents. At various points Sunday night, Wilfork will line up over right guard Alex Boone -- and, on the next play, shift in front of left guard against Iupati.
"Everybody in the league is a great player, but there's something special about Wilfork," said Iupati, who was watching the "Monday Night Football" game last week.
Against the Houston Texans, Wilfork's forced fumble on a sack of Matt Schaub set up the Patriots' third touchdown.
Iupati, no pushover at 6-foot-5, 331 pounds, has never faced Wilfork. Instead, he pointed to the educational experience of taking on the Baltimore Ravens' 335-pound Haloti Ngata, who had two sacks against the 49ers in a Thanksgiving night meeting last season.
"We need to go out there and bring our 'A' game," Iupati said.
Carlos Rogers vs. Wes Welker
The old line about cornerbacks is that they're alone on an island. Not this time. Rogers acknowledged he'll need a village to help slow down slot receiver Wes Welker, who leads the NFL in receptions since 2007
Rogers will line up against him a lot, but he has no delusions about handling Welker one-on-one. He'll be counting on safety help from Dashon Goldson and from a pass rush that needs to get to Brady so that "he's not just sitting back there baking a cake and picking us apart."
Welker is poised to lead the NFL in receptions for a fourth time. The only other players to do that are Don Hutson, who did it eight times, and Lionel Taylor, five. (Nope, not Jerry Rice, who did it twice.)
Welker also leads the NFL with 3,884 yards after the catch since 2007. That puts him 1,099 yards ahead of the next closest guy: Baltimore's Ray Rice (2,785).
49ers defense vs. The no-huddle
Late in the Patriots' 42-14 victory over the Texans on Monday night, ESPN cameras caught Houston defensive end J.J. Watt struggling to catch his breath. That's what can happen against an offense that rarely eases up on the gas pedal. The Patriots' no-huddle offense can be maddening for opponents, who never know when it's coming -- or when it will stop.
"They'll try and speed it up. Try to get you confused to where a play will be over and -- bam! -- they'll try to get up and run the next play immediately," 49ers defensive coordinator Vic Fangio said.
It isn't just a strategic challenge. It's also a cardiovascular test. By snapping the ball quickly, the Patriots can prevent opponents from making substitutions, which means lots of gasping defenders.
"We'll have to have all our guys in shape," Francois said. "You've got Ahmad Brooks, Patrick Willis, NaVorro Bowman. You've got guys who can play it. That won't give us no problem."
The hurry-up Patriots average 36.3 points and 425.7 yards per game, both tops in the NFL. Twice this season, the Patriots have scored 35 points -- in one quarter.
Brady vs. 49ers safeties
Because the 49ers front seven are so solid against the run, even while in the nickel packages, Goldson and Whitner can focus on Brady's passing targets. "I wouldn't call it an advantage, though," Whitner said. "I would say that it just evens things out."
The 49ers safeties still must contend with an unpredictable scheme directed by a thinking-man's quarterback. On any given play, Welker and shifty tight end Aaron Hernandez will run different routes based on whether they're getting man-to-man or zone coverage -- yet Brady always knows where to find them.
"You have to understand that (Brady) wants to read us," Whitner said. "He wants to get the information from the defensive backs and the linebackers based on presnap alignments and things that we do. When we play a quarterback like this, we really have to study ourselves as much as we study him. We have to know what he's looking for out there on the football field."
If all else fails with the brains, the 49ers must resort to brawn. The Patriots specialize in yards after the catch because Brady specializes on getting the ball to his receivers in space.
How many threats do the 49ers need to stop? In a game against the Bills this year, New England had two 100-yard rushers (Brandon Bolden and Stevan Ridley), two 100-yard receivers (Welker and Rob Gronkowski) and a 300-yard passer (Brady).
Still, Brown is undaunted.
"Big-time players show up in big-time games," he said. "I think we're used to the pressure. Us as a team, we'll be ready. We'll prepare. We'll put our best foot forward and go out there and plan on getting a win."