John Mackey, who passed away Thursday morning, revolutionized the tight end position. He turned it into a legitimate receiving spot and helped spur its evolution so players such as Kellen Winslow and Kellen Winslow II, Shannon Sharpe, Tony Gonzalez, Dallas Clark and so many others could capitalize.
Mackey played in the 1960s and '70s, weighing about 225 pounds. At his size and with his ability, he'd probably be an Andre Johnson-type wide receiver in today's game. Mackey was a trendsetter and, to some, is the greatest tight end to ever play the game.
There are players in nearly every generation who take things to a new level. Let's look at some current candidates who might be able to prompt change, at the very least in perception, if not the actual role of their position in the NFL.
Chris Johnson, RB, Titans
We've heard that speed kills, and Johnson has made that more than a myth. He's also starting to shed the belief that workhorse backs have to be big, bull rushers who can dish out as much punishment as they absorb.
At 5-foot-11 and 191 pounds, Johnson has 925 carries and 137 receptions for more than 5,600 yards in just three seasons. Injuries haven't been an issue. If he makes it through a fourth season carrying such a load -- and recent draft picks such as Kendall Hunter and Taiwan Jones prove serviceable -- more teams could look away from size and base evaluations of running backs on speed and durability.
Vernon Davis, TE, 49ers
What set Mackey apart from most tight ends throughout history was he wasn't just a chain-mover. He was a big-play receiver. Davis ventured into that category last season, averaging a whopping 16.3 yards per reception. That's simply not what tight ends do. The best typically average around nine or 10 yards per catch. Only once has Davis averaged less than 11.5 yards per reception.
Davis' ability to stretch the field vertically and gain yards after initial contact set him apart from just about all other tight ends, except for maybe Indianapolis' Dallas Clark, who plays more like a slot receiver. If Davis can piece together a few more seasons with such sizeable averages, he might not only change how tight ends are used, but how defenses are played.
Maurkice Pouncey, C, Steelers
The fact that Pouncey received two votes for NFL Offensive Rookie of the Year honors, was named to the Pro Bowl and made second-team All-Pro tells you how special he was after only one season. An injury that kept him from playing in the Super Bowl was one of the top storylines leading up to the Steelers' loss to the Green Bay Packers.
At 6-4 and 303 pounds, Pouncey is one of those rare players at a position that's often overlooked. The fact he was such a difference maker along a shaky offensive line shows that the only player other than the quarterback who touches the ball on every play can be just as vital to the front as a guard or tackle -- especially in this era where 3-4 nose tackles, such as Green Bay's B.J. Raji and New England's Vince Wilfork, are becoming more dominant.
Great centers don't come along often, but Pouncey, especially at his size, could be the next in line.
Ndamukong Suh, DT, Lions
Suh is one of those freakish players who every team wants but comes around only so often. He had 10 sacks from the defensive tackle position, which is eye-popping, especially since he was just a rookie. Now he will command a lot more attention, which could mean him being moved between end and nose tackle at times to find favorable matchups.
Every team wants versatility out of players, but because of Suh, finding that defensive lineman who can be interchangeable because of his size, smarts and ruggedness is a premium. Again, players like Suh are rare, and finding folks to fit the mold won't be easy. However, being able to design defenses and scheme play calls because of a front-four player's versatility could prompt the next tweak in defensive strategies throughout the league.
Mario Williams, OLB; Wade Phillips, defensive coordinator, Texans
Williams hardly will be the first 4-3 defensive end to be moved to a 3-4 linebacker. That happens all the time. But with his versatility and size (290 pounds), Williams could be one of the first to shift from a 3-4 outside linebacker to five-technique end if needed as a run stuffer or because of a creative scheme adjustment.
Williams also could be used as an edge rusher in his base 3-4 set. However, he could be reduced inside to end (quasi tackle) with a linebacker stacked behind him, or placed outside of him on the line of scrimmage in unusual sets to forge matchup problems.
Nobody knows if moving Williams to outside linebacker will work, although it's hard to question defensive coordinator Wade Phillips, who will find a way to make it work. If he also can create a new "hybrid" defender -- we usually hang that label on an edge pass rusher, but in this case it could be more of a "hybrid 2.0" defender -- that could prompt another shift in defensive strategies around the league.
Follow Steve Wyche on Twitter @wyche89.