It’s seldom that a canned head coach is worthy of sympathy. Usually he’s done enough bumbling that his demise is easily predicted (think Tony Sparano in a few weeks), or he’s drawn the ire and angst of a passionate fan base for long enough that ownership has no choice (think Andy Reid in a few weeks, maybe).

Todd Haley, however, is the exception.

Haley has been fired by the Kansas City Chiefs, with the team announcing the move through a statement Monday morning, and later saying that defensive coordinator Romeo Crennel will serve as the interim head coach. He joins Jack Del Rio in the 2011 coaching graveyard, and he’ll be left to wonder how this season could have been different if the Chiefs were able to stay even moderately healthy.

Both team owner Clark Hunt and general manager Scott Pioli were quick to highlight Haley’s lack of forward progress this year after a promising 2010. By sheer numbers alone, they’re right. The Chiefs are currently last in the AFC West at 5-8, meaning they’ll have to win out to finish at .500 one year after they won their division and finished 10-6.

Haley will leave KC after three years with a head coaching sample size that makes last year seem like an aberration, with that 10-win season sandwiched between seasons with four and five wins, and an overall record of 19-27. For Pioli and Hunt, this year’s regression far outweighed last year’s progression.

“Todd helped this team in many valuable ways over the past three seasons, and I am thankful for his contributions,” said Pioli. “Unfortunately, we have not been able to establish the kind of consistency we need to continue to build a strong foundation for the future and we believe a change is important at this time.”

Inconsistency for the Chiefs was rooted primarily in a simple lack of scoring, a damning fault for an offensive-minded coach. The Chiefs tossed 27 touchdown passes last year, and that number sits at 12 for 2011. Haley’s offense also ranks 31st in points per game with 13.3, a woeful output that’s behind other offensive wastelands in Indianapolis and Cleveland, and the Chiefs are one of just six teams averaging fewer than 300 total yards per game offensively (293.8).

But now we return to our reason for sympathy that shows why coaching in the NFL is a cruel and unforgiving profession. Those poor offensive numbers are largely the result of injuries, a rash of red cross visits that started in training camp when promising young tight end Tony Moeaki tore his ACL. That became a fashionable injury for Kansas City, with Jamaal Charles–the running back who finished second in rushing yards last year with an incredible 6.4 yards per carry, which was behind only Jim Brown in NFL history–tearing his ACL in Week 2.

Two key young players were already gone, and Haley was waiting for Jonathan Baldwin, the hulking receiver he selected in the first round last spring, to return from a thumb injury sustained during a preseason locker room scuffle with Thomas Jones. Baldwin didn’t play his first game until Week 7, and he only had four games to develop chemistry with Matt Cassel, whose season ended in Week 10 after a thumb injury.

Then, since the football gods were using the Chiefs as their own personal stress ball, Pioli acquired Kyle Orton when he was waived by the Broncos. Orton lasted one play before he too was claimed by the Chiefs plague, injuring his finger on his first pass attempt.

Between Charles and Moeaki alone, the Chiefs lost 2,491 yards of their offense from last year, a staggering number that doesn’t include Baldwin’s absence, or the significant drop from Cassel to Tyler Palko. And I haven’t mentioned Eric Berry yet either, the safety who made the Pro Bowl in his rookie season last year after four interceptions and 92 tackles, and then tore his ACL in Week 1.

The NFL isn’t supposed to be fair, and sure, there are teams like Houston that have valiantly battled through injuries. But the Texans are the outlier, not the norm, and this year in Kansas City we saw what a team usually looks like after a decimation.

Haley’s contract was expiring at the end of the 2012 season, meaning Hunt was left with three options: give him an extension, fire him, or let him enter his lame-duck season. Option No. 1 wasn’t favorable among the fans because of the team’s record, and No. 3 is a position NFL franchises try to avoid. That left Hunt with only option No. 2, despite the injuries. That’s the NFL, and that’s coaching.

The rumor mill is already churning out names, and Josh McDaniels could be a prime candidate to replace Haley given his connection with Pioli from their days in New England.

If McDaniels is hired, Haley hopefully won’t extend his version of a congratulatory handshake to his successor out of courtesy. That won’t end well.