Try this backfield on for size

Clockwise from left: John Kuhn, B.J. Raji, Quinn Johnson, Tom Crabtree and T.J. Lang are a big deal. Sean Hintz/ESPN.com

ARLINGTON, Texas -- It began nearly two months ago with a few earnest conversations, prompted by the Packers' anemic running game, in the meeting rooms beneath the stands at Lambeau Field.

Green Bay's mega-jumbo package made its first appearance in early January on the goal line in Atlanta. And then it flowered -- in spectacular fashion -- against the Bears in the NFC Championship Game when Aaron Rodgers spilled into the end zone.

"I only weigh 245 pounds," blocking tight end Tom Crabtree said. "I'm probably the guy holding us back."

"Standing out there with them, I look -- and feel -- small," fullback Quinn Johnson, who weighs 263 pounds, said at Tuesday's media day. "I don't know how you stop something like that."

Clearly, neither do the Falcons or Bears, which should give the Pittsburgh Steelers some serious pause in Super Bowl XLV. The Packers have run the play they call "32 Lead" twice -- and they've scored both times.

"Hey, that's right," said T.J. Lang, a 318-pound offensive tackle who lines up as a tight end. "You can't beat 100 percent."

The backfield is a daunting 850-pound, three-headed monster of defensive tackle B.J. Raji and fullbacks John Kuhn and Johnson. Rookie Bryan Bulaga, the 314-pound, first-round draft choice, lines up in Lang's right tackle spot. All told, there are seven 300-pounders, and even with lightweight Rodgers tipping the scale at 225, the official total is 3,198 pounds -- better than 1.5 tons and an average of 290-plus pounds per man.

This begs the obvious question: Could this be the heaviest 11-man unit in the history of football?

"I have no idea," said center Scott Wells, who is listed at 300 pounds. "Isn't that for you guys to look up the stats?"

The Elias Sports Bureau has a sterling reputation, but the answer, for the record, is nowhere to be found in its vast archive.

"Coach [Mike] McCarthy had talked about it for some time," running backs coach Edgar Bennett said. "He had a vision."

That quirky concept included a channeling of William "The Refrigerator" Perry, the Bears defensive tackle who found fame as a part-time running back during Chicago's superb 1985 season. Raji, listed at 337 pounds, is the biggest and perhaps most critical piece in the Packers' so-called elephant package.

"Really, 337?" Lang asked with a raised eyebrow. "That's a little lie."

Raji, who probably is closer to 360, got the call when Green Bay was preparing for the Falcons game.

That's 340 pounds of man meat behind me if I screw it up. You worry about it, because that's one big-ass fullback.

-- Guard John Sitton

"They pulled me out of the meeting and told me I was going on offense," Raji told ESPN last week. "I was kind of shocked."

He sat with Bennett in the offensive meeting room, going over the finer points of the formation.

"Pretty simple," Raji continued. "Line up right behind the [right] guard. Hit the tackle's hip. Just kind of clear the hole. Keep your feet running. Because you don't want to plug up the hole, obviously, for the Kuhn."

It worked perfectly against the Falcons as Kuhn scored from 1 yard out to tie the score at 14 in the Packers' 48-21 victory. According to Bennett, Raji did his job and was credited with a knockdown. In Chicago, Rodgers faked a handoff to Kuhn, pump-faked, rolled out and sprinted into the end zone for a 1-yard touchdown that gave the Packers a 7-0 lead.

Raji is exceptionally agile, even for the ninth overall pick in the 2009 draft. His uncommon size and acceleration leave right guard Josh Sitton (318 pounds) in a more vulnerable position than the opposing defense.

"Yeah," Sitton said, "that's 340 pounds of man meat behind me if I screw it up. You worry about it, because that's one big-ass fullback."

When Kuhn scored against the Falcons, one of the Packers' trainers approached Raji on the sideline.

"He goes, 'You look like The Fridge out there,'" Raji related. "And I'm like, 'Man, I'm The Freezer.'

"Just having a little fun with it, just playing around. I was probably about 1 year old when [Perry] was playing, so to sit here and say I've seen a lot of him, I would be lying. That is a name that is going to go down in NFL history forever, so even bringing his name up with my name is an honor."

One of the pressing questions this week in Texas is whether Raji will carry the ball against the Steelers. In Super Bowl XX, with the Bears leading the Patriots 37-3 in the third quarter, coach Mike Ditka gave the order and Perry scored on a 1-yard run.

Not one of the 10 participants in 32 Lead interviewed Tuesday was willing to say for sure whether Raji will be employed as a runner. Still, Lang -- rolling his eyes -- revealed some possible further wrinkles to watch for.

"Yeah," he said, "we've got some reverses and flea-flickers designed to come out of that package, too. We'll see if the game plan allows the coaches to make those calls."

Greg Garber is a senior writer for ESPN.com.