This past December the Arizona Diamondbacks dealt outfielder Carlos Quentin to the Chicago White Sox in exchange for minor leaguer Christopher Carter. While the move went relatively unnoticed at the time-as Arizona then added Dan Haren to its starting rotation in a blockbuster trade with the Oakland Athletics-it has had a significant impact for both parties.

The Diamondbacks were able to make this deal after locking up left fielder Eric Byrnes to a three-year, $30-million contract, bringing back the so-called "heart and soul" of the 2007 playoff squad after he put up the finest season of his career. Year one has not gone according to plan for Byrnes, however, making the decision already look like a colossal mistake. He has been plagued with injuries, and was not effective when he was healthy enough to stay on the field.

Which has called into question the decision to part ways with Quentin, a former first-round pick out of Stanford University who at one point was on the best position player prospects in the organization. But the young outfielder, also sidetracked with injures, did not impress during his first two stints in the majors after being called up at 23 years old. While he hit just .214/.298/.349 in 81 games before going on the shelf permanently, causing his status to drop a bit and impacting the choice to lock up Byrnes, he did not get a great look in a small sample size while battling injuries.

It is easy to analyze each decision at this point, as hindsight vision is 20/20, but this player swap has proven to be a steal for Chicago general manager Kenny Williams.

The return on investment in the Byrnes' deal looks poor (at best), and the remaining dollars left on the deal will not come off the books until 2010.

Making matters worse, Quentin is perhaps the frontrunner for MVP in the American League and has emerged as one of the most productive young hitters in the game.

In fact, Quentin, 25, has been an absolute monster in his new city, batting .284/.382/.565 with a league-best 32 home runs to help the surprise White Sox jump atop the Central. Chicago, 66-52 and tied with the Minnesota Twins for first place in the division, has been a major surprise, and the new acquisition has been one of the biggest reasons why.

It is safe to say that Quentin he has been a pleasant surprise as well.

"I thought he could be a 30-home run guy," Williams recently told the Sporting News, "just not by August."

Along with Jermaine Dye (28 home runs, .930 OPS, 73 RBIs), Quentin has helped carry the offense while several veterans got off to rough starts.A first-time All-Star in July, he currently ranks first in the AL in home runs, third in RBIs (90), fourth in slugging percentage (.565) and fifth in OPS (.948). While it would be easy to make a case for Texas Rangers stars Josh Hamilton and Ian Kinsler, or even Alex Rodriguez of the New York Yankees, there is no denying how important he has been for his team.

Hamilton stole the show at the Home Run Derby, has provided fans with a remarkable story and is pacing the majors with 112 RBIs. The combination of the RBI figure and comeback tale of hope will certainly prompt many writers to vote for him come award season. While he has certainly cashed in to drive in a lot of runs, though, he has had nearly 45 more plate appearances with runners in scoring position than Quentin. Kinsler and co. have been setting up the table nicely for him, which is a major reason why the Rangers have scored more runs than any other team. Again, the reason for the huge gap in RBI totals between the pair-which some writers will cite as a reason not to vote for Quentin-has more to do with opportunity than anything else.

And, to his credit, Quentin has been nearly as productive when his team needs him the most, hitting .345/.448/.644 with runners on base. With runners in scoring position he has been just as clutch, posting a 1.034 OPS.

Which is why it is truly is difficult to imagine where the White Sox would be without Quentin.

Carter, one of the top prospects in the White Sox's farm system at the time of the deal, was one of six minor leaguers included in the Haren deal less than a week later. Considering how well the right-hander has done alongside Brandon Webb, he certainly played a small part in the D'Backs' success.

Still, though, Arizona has struggled to score runs after a torrid April. The club ranks in the middle of the pack in most offensive categories, from home runs to OPS, as it has relied on its front-end starting pitching to help it remain afloat after floundering such a commanding lead in the West. Although they claimed slugger Adam Dunn off waivers and worked it an ensuing deal with the Cincinnati Reds to help cure the offensive woes early this week, they certainly could have used Quentin's production. If he remained with the franchise, perhaps the gap between the Diamondbacks and Los Angeles Dodgers would be much larger. It is even easier to imagine Quentin and Justin Upton playing alongside each other in the outfield at Chase Field for years to come.

While dwelling on the past does not accomplish anything, it is tempting not to do so here. If Arizona misses out on the playoffs, several similar articles will probably reappear doing exactly that.

There are a few lessons to learn from this, though. First, general managers should think twice before deciding to give up on a player based on their performance in the majors over too small of a sample size-especially so when injuries have played a factor.

Also, teams should be more careful in rewarding players for a single, career-best performance. From Byrnes to Gary Matthews Jr., too many mediocre, near replacement-level players are undeserving multi-millionaires, when there are often times more cost-effective, internal options available.

To reach Tyler Hissey, send an email to TylerHissey@gmail.com.