ALLEN PARK, Mich. -- You know the look. It comes with a low whistle and a slight blush. The head swivels in all directions. Did anyone else see what I just saw? Finally, there is a quiet laugh as you thank the good Lord it happened for your team and not against it.
Such was the reaction Calvin Johnson inspired this summer at Detroit Lions training camp, where grown men heard a clicking sound and realized only later it was their knocking knees. Johnson, the second overall pick of the 2007 draft, reported to camp in perfect health, with refined mechanics and big plans to take over the NFC North.
Because he plays in Detroit, home of the perennially underachieving Lions, Johnson's summer exploits have gone largely unnoticed. That oversight is about to change.
"It's like a veil has been lifted," Lions receivers coach Shawn Jefferson said after a late-afternoon training camp practice. "It's just been awesome to watch."
756 yards) was underwhelming relative to the enormous expectations he generated?
First, a back injury that limited him considerably over the final 12 games last season has healed. Second, the Lions have dumped the complex passing offense of former coordinator Mike Martz and are running a scheme they hope will give Johnson more freedom to make plays. Third, Johnson spent much of the offseason refining footwork issues that should help a man of his size -- 6-foot-5 and 239 pounds -- run more precise routes.
Johnson is the type of modest competitor who smiles politely after tossing you aside to make a circus catch. So he simply grins when the topic of his eye-opening summer comes up.
"Things have just slowed down on me," he said. "I'm not making any mistakes out there. I'm running good routes. But the main thing is that things have slowed down for me now that I'm in my second year.
"People have told me I would see a big change after my rookie season, and I've seen a big change."
Johnson caught a touchdown in his first two NFL games in 2007 before suffering the injury Sept. 23 at Philadelphia. He sat out the Lions'
next game, and he admitted that he was able to play in the remaining 12 games only because he took two Vicodin pills every Sunday morning.
The treatment deadened the pain, but it couldn't do anything for Johnson's decreased agility and slower movement.
"He never said anything about it," Lions coach Rod Marinelli said. "He just quietly did his job."
That's what got the Lions so excited this summer. Unencumbered by the injury, Johnson put on full display the physical attributes that made him -- in the words of Minnesota coach Brad Childress -- a prospect "with no downside."
Said Marinelli: "You watch him and it's just unique. The NFL probably only has 10 guys like that, who can do the things he does."
On one August afternoon, Johnson lined up at the far left of the offensive formation. Cornerback Travis Fisher positioned himself near the line of scrimmage, and safety Kalvin Pearson cheated a few steps left to set up a bracket coverage.
At the snap, Johnson took off on a go route. He toasted Fisher with a modest swim-like move; Fisher lost ground on every step thereafter.
Pearson's angle left him at least 10 yards too shallow when Johnson spotted the ball. There was so much separation against this supposed double-team, in fact, that Johnson had ample time to stop running, turn toward the line of scrimmage and haul in Jon Kitna's underthrown pass.
It was so smooth and surgical that it took you a moment to realize what had happened. Fellow receiver Roy Williams, never at a loss for words, felt compelled to point it out.
"See that?" Williams called out to a reporter standing on the sideline, as if picking up an earlier conversation. "Did you see that? That's what I'm talking about. That's it, right there."
Such plays were commonplace at Lions camp this summer, a tribute to Johnson's healthy back as well as the Lions' new offensive philosophy.
Marinelli eliminated the complexities of Martz's pass-oriented scheme to focus more on the running game. The smaller playbook, according to Jefferson, will ultimately give Johnson more freedom.
"Last year our offense was complicated," Jefferson said, "and boy, he just didn't look as fast on the field because of the complexity of the offense. But this year, he's really freed up. It's like the weight has been lifted off his shoulders. I really know when he's running fast, because when he's running fast, it doesn't look like he's running.
"He's just loping. He's like a gazelle. Every stride is literally like 5 or 6 yards. That's what we want."
This season, of course, Johnson will face better corners than Fisher and more accomplished safeties than Pearson. To that end, he spent much of the offseason refining his footwork with Jefferson. Specifically, he wanted to improve his efficiency going into and out of his cuts -- a particularly difficult task for a 6-foot-5 receiver.
"You can have the size and the height and the coordination and the speed," Jefferson said, "but if you can't control your speed and get in and out of your breaks, a person off the street could cover you in your routes. ... It's rare to find a big, tall guy like Calvin who can sink his hips, drop his weight and accelerate coming in and out of cuts. It's hard. But just to see how much better he's gotten at that, it just blows our mind."
Half-jokingly, Jefferson added that his most important job this summer was "making sure Calvin stays healthy." To that end, the Lions played him sparingly during the preseason, but they consider his inactivity to be the proverbial calm before the storm.
Not that you'll hear Johnson complaining -- or that you'll even hear him. The only running Johnson does is on the field. His mouth remains steadfastly in neutral.
"I don't really feel any need to tell everyone what's coming," he said. "I feel like it will take care of itself based on how I play."
Kevin Seifert covers the NFL for ESPN.com