Safe to say the Patriots do not do business the way most teams do, and their success is hard to argue with. Welker’s age and injury history may work against him for a long-term deal, but his production and consistency cannot be ignored.

It begs the question if the Patriots simply view Welker as a replaceable talent, despite the fact that their focused use of him in the slot is one of the most unique experiments in NFL history.

In today’s NFL, a top-flight passing attack benefits from a solid slot receiver, and if the best in the business is not being locked up long-term, then it is worth further examination as to why.

Welker: One of a Kind

Maybe it was not the best offseason to seek a new big deal when everyone remembers your Super Bowl performance for the failure to haul in a difficult pass in the fourth quarter.

Since 2007, Wes Welker has 554 receptions in the regular season. But only 11 of those receptions have been caught on passes thrown 20+ yards in the air, such as this pass was. That’s only 1.99% of his receptions. One of those passes was by Matt Cassel in 2008, leaving just 10 career connections between Brady and Welker on passes over 20 yards down the field in the regular season.

In seven playoff games together, Welker doesn't have a reception longer than 19 yards no matter where the pass was thrown to.

The Patriots use Welker on plays that utilize his strengths, and going down the field on vertical routes is obviously not one of them. He does his damage within 10 yards from the line of scrimmage, and much of it comes after he gets the ball in his hands.

I have studied over 60 of the most productive wide receivers from the last two decades, and found that Welker leads them all in two key categories:

• Welker’s 71.9 percent catch rate ranks No. 1. He has caught 650 of 904 career targets.
• Welker has gained 52.02 percent of his yards after the catch, which gives him the highest YAC percentage.

New England is no stranger to utilizing a slot receiver as their primary. The player who came in second in my study was Troy Brown, who caught 66.31 percent of his targets and had a 45.1 YAC percentage in his 15-year career with the Patriots.

You can see Welker is even better than Brown was. Here is Welker’s yearly receiving breakdown:

Welker’s game is also not quarterback dependent because of all the short throws. He caught 67 passes (and 67.0 percent of his targets) in 2006 with the Miami Dolphins, who had Joey Harrington, Daunte Culpepper and Cleo Lemon at quarterback.

When Brady missed nearly the entire 2008 season, it was unproven Matt Cassel stepping in and completing 108 of 144 passes (75.0 percent) to Welker.

It’s not the quarterback, but it definitely is the New England system that allows Welker to thrive without wasting him on plays his skill set is not best suited for. They maximize his talent, which is still unique as it takes a certain receiver to fight for so many of his yards in a running back-esque manner.

But the limitations in Welker’s game may be a strong reason why he is not going to be paid in the upper range of receivers, such as Larry Fitzgerald and Calvin Johnson.

All three players may be a No. 1 wide receiver on the depth chart, but their responsibilities and play style could not be more different.

Playing the Other Slot Machines

While Welker is consistently used in a unique manner, the league has seen its fair share of other quality slot receivers that do things much differently.

Victor Cruz exploded onto the scene with the New York Giants last year. Exploded is a good word, as he made his name on big plays down the field. Cruz had 12 receptions on passes thrown more than 20 yards in the air last season, which is one more than Welker has had in five seasons with the Patriots.

As The Wall Street Journal via data from Pro Football Focus pointed out, Cruz was a better slot receiver than Welker last season. If he continues to produce big plays in New York, you can count on Cruz to be paid handsomely in due time.

The record-setting pass offense of 2011 was in New Orleans, and Marques Colston has been a go-to guy for Drew Brees since arriving in 2006. At 6’4”, Colston plays big and can do real damage in the slot, especially on those seam passes Brees excels at.

Colston catches 64.98 percent of his career targets, which was third behind Welker and Brown in my study. He is also usually good for about eight touchdowns a season, and his height makes him a capable red zone target.

One of the problems, if you can call it one, with Welker’s popularity is the stereotyping it creates when people talk about wide receivers. These days if a guy is smaller, plays in the slot, and is white, he becomes the next “Wes Welker” in the media.

This is simply not fair or accurate, but without dwelling on it, there are black receivers like Eddie Royal (especially in his rookie season with Denver in 2008) and Davone Bess who are very much like Welker in the slot.

Like Welker, Bess came from a run-and-shoot offense in college (Hawaii), and he joined the Dolphins two years after Welker went to New England.

If Bess played in an offense that catered so well (and so consistently) to his strengths, he would likely have Welker numbers each season himself. He is another receiver that will not beat you down the field, but is shifty and great with the ball in space.

Austin Collie is a player some loved to compare to Welker while he was still healthy and playing with Peyton Manning in Indianapolis. In 2010, Collie caught 58 of his 71 targets (81.7 percent) and was ready for an All-Pro season had it not been for multiple concussions.

Unlike Welker, Collie was still used on intermediate and deep routes. That’s how Peyton Manning plays quarterback, and the Colts will always look for big plays if possible.

The first play was a go-route right down the middle from the slot, and Collie beat his man for a huge 46-yard gain, which was followed by a 16-yard touchdown.

Similarly, Collie crushed the hearts of Denver fans in 2010 on a late fourth quarter drive. On a 3rd and 15, he again went down the field from the slot to make a 48-yard catch after beating cornerback Nate Jones. Four plays later, Collie lined up at flanker and beat Perrish Cox one-on-one for a 23-yard touchdown to ice the game.

If Collie stays healthy and Andrew Luck is the real deal, you might see him return to his early success.

In Denver, Manning will look at Eric Decker as his new Collie. Decker was no stranger to going deep last year with Tim Tebow, and you can bet Manning will test the defense with him all over the field as well.

The quarterback has a lot to do with how the receivers are used. Brady and Welker have never bothered to establish a deep connection, because they feel more confident in playing to their strengths.

You can admire the Patriots’ strategy, though it does leave their offense limited, which has been a problem in these playoff games against tougher defenses like Baltimore and the New York teams.

The Perfect Replacement?

When you look at the skill set and the way he is used in the New England offense, one could easily make the argument that Welker is more replaceable than some of the other slot receivers in the league.

If there was a clone for Welker, New England may already have him with Julian Edelman. A quarterback at Kent State, Edelman was drafted in the seventh round in 2009 and did a great job filling in for Welker that season.

Edelman is even a better return specialist, as he averages 12.4 yards per punt return (2 TD) compared to 10.1 yards per punt return for Welker (0 TD).

In the 2009 AFC Wild Card game against Baltimore, with Welker sidelined because of a torn ACL, Edelman made one of the most incredible effort plays you will ever see. Click here for full-size image.

It was 4th and 7 at the Baltimore 39. The Patriots for some reason ran a screen, though there was little blocking available to Edelman, who caught the ball about four yards behind the line of scrimmage (1).

After putting a move on Chris Carr, Edelman had more trouble with Terrell Suggs and Frank Walker closing in (2). Edelman stopped on a dime, took a few steps back, lunged forward into a crowd that now included Ray Lewis, and took contact about four yards short of the first down (3).

Edelman met part-time boxer Tom Zbikowski head on (4), and still had enough to lunge forward and get the first down (5). That was enough to make Wes Welker applaud from the press box (6).

Unfortunately, the play did not count because of a penalty, but Edelman picked up the first down anyway with a 24-yard catch on 4th and 17. Remember, in seven playoff games Welker has never gained more than 19 yards on any catch.

Edelman has only seen 22 targets the last two seasons as he has a bigger role on special teams, but if Welker was injured or did not return in 2013, then his replacement may already be available to the Patriots.

The slot might already be filled.

Scott Kacsmar is a football writer and researcher who has contributed large quantities of data to Pro-Football-Reference.com, including the only standardized database of fourth quarter comebacks and game-winning drives. You can visit his blog for a complete writing archive, and can follow him on Twitter at @CaptainComeback.