Robert Mathis Is an Irreplaceable Loss for the Indianapolis Colts

The Indianapolis Colts have undergone drastic changes over the last three years. 

That's not news to anybody, is it? We can all agree here? 

Whether it's the general manager, coaching staff, star quarterback, coaching philosophies, maligned running back, speedy wide receiver, disappointing defensive players or overachieving undrafted free agents, the Colts of today look nothing like the Colts of the Peyton Manning/Bill Polian era, an era that officially came to a close less than three years ago. 

Change is fine, even good in many cases. But too much change, too much youth, is cause for instability. Every organization needs its rocks, the ones that are relied upon day after day, week after week, year after year. These may not be the ones in the most glamorous positions, but they are critical for seamless transitions. 

Joe Robbins/Getty Images

For Indianapolis Colts, those players are Robert Mathis and Reggie Wayne. There's no debate, no room for suggestion here: Mathis and Wayne are the heart-and-soul of the Colts. When push comes to shove, the two have been the team's steadying forces. On offense, Wayne is the one that Andrew Luck looks to on crucial third downs. When the defense needs a key turnover, one could feel a Mathis strip-sack coming. 

The two are incredibly consistent: Wayne has caught at least three passes in 72 consecutive regular season games, an NFL record, and he is the league's oldest wide receiver at 35. Mathis is one of seven players in NFL history with at least seven sacks in 10 straight seasons. 

There are other veterans in Indianapolis, but none like Mathis and Wayne. Adam Vinatieri is still best known for his clutch kicks in New England despite this being his ninth season in Indianapolis. Cory Redding is a high-energy leader that likely is undervalued, but his two seasons as a Colt pale in comparison to Mathis and Wayne, the "lifers."

And between the two? Well, let's just say that Wayne owes the 33-year-old Mathis a favor. When Wayne's body betrayed him last October, and an ACL injury forced him to miss the back half of the 2013 season, Mathis stepped up and was the veteran rock that the Colts needed him to be.

Over the last two seasons, Mathis has taken the burden of being a dependable veteran to new heights. When Dwight Freeney struggled to make the switch from 4-3 defensive end to 3-4 outside linebacker, Mathis took the pass-rush lead with eight sacks from his unnatural spot at strong outside linebacker (SOLB). Oh, and he also threw in the first interception of his career. 

Ronald Martinez/Getty Images

In 2013, with Freeney and Jerry Hughes (Indianapolis' third-best pass-rusher) both in new cities, Mathis took the burden upon himself again. Back in a role best suited for him (rush outside linebacker), Mathis finished the season with a league-leading 19.5 sacks and 10 forced fumbles, tying the league record as the fourth person ever recorded with 10 forced fumbles in a single season. 

It didn't end in the regular season, either, as Mathis has had a sack in each of the "new era" Colts' three playoff games, including a critical strip-sack of Alex Smith that helped kick-start the Colts' record comeback against the Kansas City Chiefs last season. 

There have been numerous reasons for the Colts' quick turnaround under general manager Ryan Grigson and head coach Chuck Pagano, but the decision to re-sign Robert Mathis looms large among them. 

Now, with an Achilles injury that will force him to miss the entire 2014 campaign, the pass-rushing, playmaking burden that has rested on Mathis' shoulders for the last 10 years is waiting to be picked up by somebody else. 

As of this moment, it seems rather unlikely that person will come from the Colts' base pass-rushers (defensive linemen, outside linebackers). 

Player	Snaps	Pass Rush Snaps	Pressures	Pass Rush Grade
Cory Redding	57	30	1	+0.4
Josh Chapman	41	18	0	-0.9
Arthur Jones	56	26	0	-1.4
Erik Walden	66	25	1	-1.1
Bjoern Werner	62	26	0	-1.2
Zach Kerr	25	14	0	-0.7
Ricky Jean Francois	18	8	0	+0.1
Cam Johnson	5	2	0	-0.2
Jonathan Newsome	11	4	0	-0.3
Andy Studebaker	10	4	0	-0.3

The numbers for the group were horrific last season, and they continued to be Sunday night against Denver. Last season, Robert Mathis' pressure was the catalyst to sacking Peyton Manning four times and disrupting him enough to build a lead and eventually obtain a win. In 2014, the toothless pass rush got to Manning just one time and saw the Broncos build a 24-0 lead in the first four drives of the game. 

No, there is no replacing Indianapolis Colts' all-time sack leader. While Mathis is aging, he was a bona fide Defensive Player of the Year candidate in 2013, not a grizzled veteran rapidly approaching ineptitude. No one person can carry the load that Mathis has labored under for the last two seasons. 

Perhaps there is an answer somewhere, likely revolving around a lift-by-committee approach. Maybe the Colts can generate pressure with blitz packages featuring their versatile inside linebackers, enough pressure to still salvage a decent defensive unit. If Wayne turns back the clock and beats the odds in a battered body, maybe the Colts offense can put up enough points to offset the weakened defense. The coaches could raise their in-game coaching prowess to boost the team. 

But none of that will replace Mathis. How could it? How do you replace a team's defensive icon, one who ranks among the NFL's best-ever at taking down the quarterback? You don't. Ten consecutive seasons with at least seven sacks? The next-highest total for the Colts last season was 3.5. A pass-rushing savior isn't walking through the door.

Even if everything goes Indianapolis' way, it'll only make Mathis' absence more bearable, and they may make a playoff victory, and even contending for a Super Bowl, possible. 

That's all Mathis is asking for. He's been the Indianapolis Colts' rock to lean on for the last 10 years. But unless some unforeseen development happens, the Colts are about to learn that a pile of pebbles isn't quite as sturdy. 

All statistics and snap counts come from Pro Football Focus (subscription required) and Pro Football Reference unless otherwise noted. All training camp observations were obtained firsthand by the reporter unless otherwise noted.

Kyle is an NFL and Indianapolis Colts analyst for Bleacher Report and the editor-in-chief of Colts Authority. Follow Kyle on Twitter for more stats, analysis and general NFL analysis.