Silent partners

FOXBOROUGH -- In the days leading up to tonight's game, the Patriots spent significant practice time indoors, pumping loud music through speakers located close to the sidelines.

The tunes ranged from Bruce Springsteen, to '80s rock, to hip-hop, and the idea was to simulate the type of noisy environment the team's offense is expected to experience against the Vikings at the Metrodome.

Because of that noise, the offense likely will have to use a silent snap count. That, in turn, will put added stress on the team's pass protectors -- especially tackles and tight ends -- because they won't be able to hear quarterback Tom Brady.

Contrast that situation to the team's home games, when Brady has the luxury of informing his teammates of the snap count in the huddle, then barking it out at the line of scrimmage so they can hear it as the Gillette Stadium crowd is hushed. Ask most offensive linemen or tight ends, and their preference is usually to hear the snap count.

"You definitely have an advantage when you hear the count, because you know the count and the defense doesn't," said tight end Benjamin Watson. "You can mix it up, try to get them to jump offsides and stuff. You don't have that option with a silent count."

Every road team must prepare for situations in which they can't hear an audible snap count, and the Patriots' history in this part of the game took an important turn four seasons ago. That's when they tweaked the procedure in which they execute the silent count.

In short, the key people are Brady and center Dan Koppen because of their proximity to one another. When Brady is directly under center, he can communicate with Koppen either verbally or through a physical cue, such as tapping him. In turn, Koppen can then make a signal to the rest of the linemen -- such as lifting his head -- that the snap is coming in a certain amount of time.

"It's all communication," Brady said. "We started it back when we played at Houston in 2003. It really helps the O-linemen out, that there's a rhythm of the center when he brings his head up to snap the ball. You always like everyone to get off the ball at the same time, but it's hard if you're calling out a cadence and the two tackles can't hear you."

The process has an added wrinkle when Brady is in the shotgun. In that case, Brady isn't close to Koppen, so the two must rely on a visual signal -- such as Brady lifting his leg as Koppen looks back -- to start the process of the silent count.

While such visual cues often can be picked up by the defense, there is still some guesswork because the Patriots can vary the timing in which they execute their silent count. On the offensive side, one of the tough parts for tackles and tight ends is setting up to block while also seeing Koppen and the ball.

"You have to get yourself in position where you can actually see the center make his movements to snap the ball," rookie right tackle Ryan O'Callaghan said. "Sometimes it's third down and long and you have a wide end, which is tough because you also have to look toward the ball. That's the major difference. You have to turn your attention, but you can still see [the defensive end] out of the corner of your eye."

Sometimes, all it takes is a split second for the defense to gain the upper hand, which is why getting off the line of scrimmage immediately after the ball is snapped is so crucial for offensive linemen and tight ends.

"If you're trying to reach a guy [to run block], or if you have to pass block, or if you're releasing into a route, you always want to at least be moving at the same time as the defense," said Watson. "If you're late off the ball and they're coming towards you, you don't have much of a chance. It's hard enough getting someone when the playing field is even."

Patriots coach Bill Belichick stressed the importance of blockers getting off the ball earlier this week.

"[The Vikings are] really good on defense and you're talking about a Monday night game in an environment that's going to be loud and real hostile," he said. "One of the things that they do that gives you a lot of problems is they're quick off the ball. That's No. 1. No. 2 is they run a lot of blitzers up inside. So if they're able to time up that blitz so the guy is hitting the line of scrimmage right as the ball is being snapped, you don't have very much time to get that picked up. You either have to slide a lineman over in front of it, or a back has to get up and get him. Something has to happen and it has to happen pretty quickly.

"If you're a little bit late off the ball, or you don't hear the snap count and you're waiting to move when they move, and then they have the jump on you in the neutral zone, that's where some bad things happen."

The Patriots haven't had to use much of the silent count this year, because they jumped out to early leads in two previous road games -- against the Jets and Bills -- and avoided being put into a deep hole early in their road game against the Bengals.

Asked what first comes to mind when he hears the words "silent count," Watson said: "Crowd noise. Getting off the ball on time. Heightened concentration. Your senses have to be sharp.

"When you go to a place like Minnesota, or any place where it's going to be loud, you want to use the silent snap count. Sometimes you can't hear the quarterback. For me playing tight end, you have to watch the ball. What's hard about it is that you have a defensive end over you, who is probably bigger than you are, and you have to block them but you have to look at the ball before you can take off and hit him, because it's all silent. It's one of those things you have to deal with when you go away."

How the Patriots deal with it tonight -- in Minnesota's first Monday night game since 2001 -- likely will play a large role in the final outcome.

"It's hard enough to play ball going on an audible snap count," Watson said. "The silent count makes it harder. We practice it all the time."

Mike Reiss can be reached at mreiss@globe.com.