It’s the dawn of a new era in Indianapolis, and it appears that Jim Irsay will use Peyton Manning as the only buffer.

Bill Polian’s run as the team’s personnel guru is over. He and his son Chris were fired Monday in the immediate aftermath of a 2-14, Manning-less train wreck.

The move is only slightly surprising because of Bill Polian’s reputation and his long tenure in Indy. The six-time executive of the year is arguably a Hall of Famer, and he’s been called one of the brightest minds in the world of professional football.

But as Irsay said today at his press conference to announce the changes, “It was time.”

Many will claim that Bill and Chris Polian and Jim Caldwell (the head coach who has yet to be fired but may be handed a pink slip in the coming days), are the sacrificial lambs of a disastrous season. With Manning on the sideline throughout the year, the Colts crashed and burned, finishing with the league’s worst record only 23 months after appearing in the Super Bowl.

After all, Bill Polian was the executive of the year in 2009 and, gee golly, it’s hard to win without your franchise quarterback!

But I don’t think the Polians are being thrown under a bus, because it was ultimately their responsibility to ensure that the franchise was prepared with a contingency plan in the event that something happen to No. 18.

And let’s face it: they weren’t (um, Curtis Painter? Kerry Collins?). Looking beyond Manning, this is a mediocre football team with a weak defense, a shaky offensive line and a poor running game. In recent years, the Polians have struggled on draft day and been ghosts in free agency. You can’t consistently miss at the top of the draft (think: Anthony Gonzalez, Tony Ugoh, Donald Brown, Mike Pollak, Jerry Hughes) and expect to stay competitive.

Bill Polian deserves a lot of credit. Between 1999 and 2010, the Colts were 128-48 with 11 playoff appearances, eight division titles, two Super Bowl appearances and one championship. His high water mark as a general manager in Indy took place when he drafted Manning over Ryan Leaf only four months into his tenure in 1998, but he was also responsible for adding stellar complementary players to load up in the years to follow.

Did the Polians benefit from Manning’s presence to a significantly higher degree than Manning benefited from the Polians’ presence? Without a doubt. And that they struggled that badly without Manning is an indictment of the poor job the Polians did in recent offseasons. The Patriots were 11-5 without Tom Brady in 2008, so don’t tell me that a well-run team can’t succeed without its franchise pivot.

How good would the Colts have been without Manning the last decade? There was a lot more talent five years ago than there is now, but it’s become obvious that this wouldn’t have been a Super Bowl team sans Manning. So the argument could be made that Bill Polian was lucky to stay employed in Indy long enough to appoint his son, who had no credentials apart from apparently being a legacy, to the GM role in ’09.

Bill Polian had clearly begun to slip. He was living off of his reputation and the success he experienced earlier in his career, while Chris Polian was living off of his last name.

Polian and Manning will forever be linked. Manning’s arrival and emergence allowed Polian to enjoy such a long and prosperous run in Indianapolis, and when Manning finally hit a wall in 2011, he brought Polian and his son along for that ride, too.

There’s little doubt that Manning had a say in the decision to cut the Polians loose. Polian started Manning’s career, and Manning might have ended Polian’s. And if Manning wields that kind of power within the organization, that has to make you wonder what’s to come next. Will Manning have to sign off on the next personnel director? What about the next head coach (if Caldwell is fired)? And if so, is that a healthy structure for a franchise to adopt?

And then there’s the possibility that this is a sign that bigger changes are coming. With the Colts likely to use that No. 1 overall draft pick on blue-chip Stanford quarterback Andrew Luck and with a soon-to-be-36-year-old Manning due a $28-million bonus in the near future, it’s possible that Irsay decides to start anew in 2012 with a blank slate, leaving behind the Polians and Caldwell and Manning and Reggie Wayne and all of the lingering pieces from what now appears to be the previous era of Colts football.

This offseason, for the first offseason in over a decade, Indianapolis will be at the center of the football world.