[caption id="attachment_16765" align="alignright" width="216" caption="Could 2011 be the last year Pro Bowl defensive end Robert Mathis dons an Indianapolis Colts uniform? (Andy Lyons | Getty Images)"][/caption] No single aspect of modern day NFL defenses is more important than generating a pass rush. Putting pressure on opposing signal callers forces bad decisions, which lead to turnovers. In what has become a passing league, neutralizing the quarterback is key. Each team generates pressure in its own way, but few teams in the NFL rely more on the defensive end position to generate a pass rush than the Indianapolis Colts. Fortunate for Indy, it has had the luxury of boasting a tandem set Pro Bowl pass rushers who give opposing quarterbacks, offensive line coaches, offensive linemen, and offensive coordinators absolute fits. Carrying two highly paid defensive ends on one team does come with its share of consequences, of course. One of the biggest consequences for the Colts over the past six years has been the reliance on Dwight Freeney and Robert Mathis without legitimate depth behind them. Injuries to Freeney were partially responsible for derailing playoff runs for the Colts in 2007 and 2009. There was a time, prior to the 2006 season, that the Colts could fall back on Raheem Brock for additional pressure. When he was forced to bulk up and focus more on playing defensive tackle, all meaningful pass rush depth was gone. In the first round of the 2010 NFL Draft, the Colts drafted Jerry Hughes to remedy the problem. Fresh off of losing the Super Bowl to the New Orleans Saints, in no small part because the team was unable to generate any pressure on Super Bowl MVP Drew Brees, the front office decided to place a great emphasis on bolstering the depth and planning for the future. Unfortunately, Hughes has failed to turn into the Mathis-clone he was projected to become. He struggled significantly in 2010, and is partially blamed for a long kickoff return in the playoffs against the New York Jets that allowed a last second field goal -- sealing an early exit for the Colts. In 2011, he has seen more of the field -- and spends much of his time on the right side (relieving Freeney) -- but has yet to be consistent in any phase of the game. While it should be clear at this point that the decision to cut John Chick was a mistake, the front office did not rest on siding with Hughes. Instead, two veteran defensive ends were brought in via free agency. Both players have been productive, and key role-players, in helping shore up a leaky run defense -- particularly on the edges. Former first round selection Jamaal Anderson was widely recognized as one of the top run defending defensive ends in the NFL but failed to live up to the pass rushing reputation he carried with him from college. Since he has joined the Colts, his abilities have noticeably improved in that area. Anderson has only accrued one sack, but it is not indicative of his overall impact. Another former first round pick, Tyler Brayton, has picked up two sacks and generated pressure of his own. He also has lived up to his reputation as a solid run defender. The big issue with the position heading into 2012 is that three of the players mentioned above will be unrestricted free agents. Mathis, Anderson, and Brayton will all require new contracts if they are to remain in Indianapolis. Both Brayton and Mathis are north of 30 years old -- as is Freeney -- which makes prospects like North Carolina's Quinton Coples really attractive. The big issue with drafting a player like Coples is that the team has bigger needs in the secondary, and at quarterback -- particularly if Manning does not make a return. Players like Illinois' Whitney Mercilus or Oklahoma's Frank Alexander could be worth a look in the second or third rounds though. Otherwise, retaining the aging players at a reasonable price will be key. If Manning does not return, cap room will be freed up to do so. If he does, keeping the trio will be difficult -- especially if the team also drafts Andrew Luck with the number 1 overall pick. It looks like the team's long-term fate is tied to Manning and the development of second-year player Jerry Hughes at this point. How Irsay and the Polians handle it during the 2012 off-seaosn will have short and long-term implications for the future of Indy's pass rush.