Peterson, the Minnesota Vikings' star running back, has spent most of his NFL career dealing with defenses that game plan to stop him, which is exactly what Lacy, the Green Bay Packers' rookie running back, has faced the last two games.
Eddie Lacy managed just 27 yards against New York as the Giants committed to stopping the run.
Without starting quarterback Aaron Rodgers, who hasn't played since his Nov. 4 broken collarbone, Lacy has found things much more difficult. As we noted on Monday, in the last two games, the Packers have faced seven or more defenders in the box nearly twice as often in the last two games, according to ESPN Stats & Information, as they did in the first eight, when opposing defensive coordinators had to prepare for Rodgers and the Packers' prolific passing game.
Rarely in his seven-year NFL career with the Vikings has Peterson had the luxury of playing with a top-tier quarterback. Perhaps only in 2009, when Brett Favre had the better of his two seasons with the Vikings, did Peterson have that.
"When you're not really passing the ball that well, teams can focus on the run, especially when you're a run-first team," Peterson said Wednesday during a conference call with reporters at Lambeau Field. "So it makes it difficult when the quarterback play is not up to par."
While the Packers have been pleased with the play of backup quarterback Scott Tolzien, who will make his second straight start on Sunday against the Vikings, so far he hasn't convinced opposing defensive coordinators to sit back and play coverage.
"That's a perfect example," Peterson said. "Lacy, he had come in and helped their running game tremendously. But it shows with Aaron Rodgers not back there how big of a difference he makes and what he means to that offense. So that situation right there is a perfect one to look at."
Last season, when Peterson rushed for 2,097 yards (8 yards short of Eric Dickerson's single-season record), the Vikings faced seven or more defenders in the box on 61.3 percent of their snaps, according to ESPN Stats & Information.
"It's real difficult to make a play work in situations like that," said Lacy, who leads the NFL in rushing yards since Week 5 with 645 yards but was held to just 27 yards on 14 carries in Sunday's loss at the New York Giants.
"But my mindset is just try to get anything that's positive and just make sure I don't get tackled for like a loss of 1 or 2 because it can put the offense in an even worse situation."
When teams load the box to stop the run, it's simply a matter of numbers. If the Packers don't keep a fullback or tight end in to block, the five offensive linemen could be outnumbered by two or three defenders.
"At the first level, you have to make sure you're covering guys up and allowing your running back to get to that point where he's getting some one-on-one matchups with the safety down in the box and give him a chance to make that guy miss," Packers right guard T.J. Lang said. "We haven't really been executing as well as we should be."
If Lacy -- or any running back for that matter -- can avoid the initial onslaught of a loaded box, then the chance for a big play in the running game increases.
"If you can get past that unblocked guy," Lacy said, "then yeah, there's pretty much no one else back there."