If you've been paying attention at all to the Diamondbacks in 2014, you knew that general manager Kevin Towers wasn't going to be that in Arizona much longer. Even before Tony La Russa's retirement turned out to apply only to on-field work, with the Hall of Famer becoming the Chief Baseball Officer for the D'backs in May, the Diamondbacks were awful and had not been relevant since 2011, in Towers' first full season as general manager. His constant tinkering hadn't worked, much as it never brought glory to Towers' previous general managing for the Padres, and it was only a matter of time before he was booted in favor of a handpicked, La Russian replacement.

The inevitable arrived Friday morning, with Nick Piecoro reporting that Towers is out as general manager, but has been offered a position elsewhere in the organization. It is, for all intents and purposes, a firing. Towers can likely latch on elsewhere without working for people who just told him he wasn't good enough for the job he had: there have been rumors of him joining the Padres in some kind of executive capacity since June, months before he was even ousted in Phoenix, so the pressure on him to accept a job under La Russa is likely minimal. That's all educated guesswork, though: what we do know for sure is that it was time for Towers to be removed from power in Arizona.

Towers was hired by the Diamondbacks in late September of 2010, inheriting a roster that would, by season's end, lose 97 games and feature one of the worst bullpens in the history of baseball. He would send Mark Reynolds, who had legitimate power but little else, to the Orioles in order to get reliever David Hernandez and brought J.J. Putz aboard as the other. Much of the rest of the D'backs' 2011 success, in which they won the NL West by winning 29 more games than they did the year before, had a lot to do with positive regression. Justin Upton had been good, not great in 2010, with a 110 OPS+; in 2011, he jumped that to a career-high 141 OPS+, and finished fourth in the MVP vote. Backstop Miguel Montero not only played a full season, but was fantastic doing it, jumping his own OPS+ up by almost 20 points while playing in 140 games. Stephen Drew and Kelly Johnson both took steps back, but they got more production out of Ryan Roberts than they had Mark Reynolds, Gerardo Parra had a fantastic season where he was both an above-average offensive outfielder and a deserving Gold Glove winner. Chris Young continued to be a decent hitter with a great glove out in center. If Towers deserves credit for that lineup, it's in the sense he knew not to tinker too much, and for knowing they could afford to move Reynolds in order to stabilize elsewhere.

Similarly, Towers inherited a rotation ready to break out. Ian Kennedy, acquired in late-2009 in a three-team deal with the Yankees and Tigers, broke out in a huge way to become Arizona's ace. Daniel Hudson came from the White Sox a few months before Towers took over in Arizona, and the starter who many projected as a reliever flourished, posting a 113 ERA+ in 33 starts and 222 innings. Even Joe Saunders, at the time still a reliable back-end arm, was picked up before Towers came aboard, and he too did his job with a 107 ERA+ and over 6-1/3 innings per start. While the Diamondbacks struggled to find a reliable fifth starter all year, the fact Saunders pulled that off and the duo of Kennedy and Hudson both averaged 6-2/3 innings per outing took serious pressure off the bullpen.

Once Tony La Russa was involved, change was assured. (Photo credit: Norm Hall)

It's hard to explain how bad the D'backs pen was, but the simplest way might be this: the 2010 Arizona pen was so awful that it would have taken the addition of Mariano Rivera -- who had a 1.80 ERA that year -- to raise them to the replacement level. We've already accounted for many of those 29 additional wins elsewhere, but the bullpen also deserves credit for dropping their collective ERA to 3.71 after 2010's 5.74 effort.

Notice something important here: Towers identified the team's problem, correctly remedied it, and left the rest of the talented roster alone, with the only serious in-season upgrade coming through the trade of Johnson to the Blue Jays for Aaron Hill in something of a challenge trade, one Hill responded to in a big way. The result was a division title and the D'backs first playoff berth since 2007. Even though they lost in the NLDS, there was progress here. Adding young Athletics starter Trevor Cahill to the mix with an off-season trade only made that more apparent.

When 2012 didn't go the same way thanks to injuries and ineffective players -- Stephen Drew's ankle was busted from the previous summer, Hudson made just nine starts before undergoing Tommy John surgery, Willie Bloomquist continued to prove he's never the answer at any position, Ryan Roberts turned back into a tattooed pumpkin, and Justin Upton was once again good instead of great -- Towers got the itch to tinker. He dealt Craig Breslow, a low-cost, highly effective lefty for Matt Albers in July. In October, Towers acquired the expensive, aging, and ineffective Heath Bell from the Marlins in a three-team deal that cost them Chris Young in center, a bigger loss at the time than Young's subsequent decline would suggest now.

The big one, though, was Justin Upton.

Upton went to the Braves in a controversial deal that netted the Diamondbacks Randall Delgado -- a pitcher whose future was likely in relief -- a whole bunch of players you're unlikely to remember by now, and Martin Prado. This also cost the Diamondbacks Chris Johnson, who Towers had acquired just months before from the Astros. Upton has a 132 OPS+ with the Braves and is currently pacing his career-best 2011 at 142, while Johnson has had one high-quality year and one poor one for Atlanta. Prado was the centerpiece for the Diamondbacks, with Towers signing him to a four-year, $40 million extension a week after the trade: he's now with the Yankees for the last two years of that deal. The D'backs got a player to be named later and a 24-year-old Double-A hitter without a true position for him. Randall Delgado's 82 ERA+ in 181 D'backs innings doesn't begin to make up for that.

Upton was the worst of these moves, but there were more. Ian Kennedy was essentially given away for a LOOGY that the D'backs removed from their roster months later, and now, just over a year later, Kennedy has proved to be a useful (if hard luck) piece of the Padres' rotation who is still under team control for 2015. Towers not-so-secretly clashed with pitching prospect Trevor Bauer and eventually gave up, dealing him to the Indians in a three-team deal that netted Arizona Didi Gregorious, a low-offense glove at short. While the trade for Mark Trumbo made sense -- the Diamondbacks needed power and had a surplus of young pitchers -- Trumbo was hurt early on in 2014 and the D'backs young starters failed to bring them back to relevance.

The farm isn't barren, but Towers hasn't done much with it during his time in town. The big-league roster is worse now than it was when he took over. Tony La Russa was now his boss, and a change in management often means those in the middle get tossed even if things are going decently. The Diamondbacks are a mess, though, have squandered the progress they made at the start of Towers' tenure, and will now have to try again with someone new. It's not a surprise, but that only emphasizes how necessary this ousting was.