J.D. Martinez Trade Steal Makes Diamondbacks a Legit 2017 NL Threat

As the summer heat ratchets up, the race for the MLB postseason is getting real. The Arizona Diamondbacks just added legitimate horsepower. 

First, the news, courtesy of MLB.com's Jason Beck: Arizona acquired outfielder J.D. Martinez from the Detroit Tigers on Tuesday in exchange for a prospect package of third baseman Dawel Lugo and shortstops Sergio Alcantara and Jose King.

Lugo was the No. 4-ranked prospect in a relatively thin farm system, per MLB.com, while Alcantara checked in at No. 15 and King failed to crack the top 30.

ESPN's Keith Law was unimpressed, calling it a "light return" for Detroit, and Baseball America's JJ Cooper concurred. 

It's impossible to accurately grade a trade without the benefit of hindsight. Plus, Martinez is a rental, as he's eligible for free agency after the season.

For the moment, however, the Diamondbacks netted a difference-making bat for a seemingly bargain price, and they went from National League factor to legitimate Senior Circuit threat in the process.

Stephen Brashear/Getty Images

Without Martinez, Arizona ranked 10th in baseball in OPS and was tied for seventh in runs scored. Still, the offense was heavily reliant on first baseman/MVP candidate Paul Goldschmidt and third baseman Jake Lamb, as Bleacher Report's Zachary D. Rymer noted:

Now, Martinez will move into left field in place of Yasmany Tomas, who is on the disabled list with a groin injury and, despite his undeniable pop, owned an ugly .294 on-base percentage.

By contrast, Martinez was slashing .305/.388/.630 for the Tigers with 16 home runs.

If we zoom back, the stats get more impressive. Over the past four seasons, the 29-year-old is one of two big leaguers to post at least a .300 average and .550 slugging percentage, as Ryan Phillips of Thebiglead.com noted. 

The other? A fellow by the name of Michael Nelson Trout.

Martinez also addresses the Diamondbacks' yawning deficiency against left-handed pitching. Arizona ranks next-to-last versus southpaws with a .223 average, ahead of only the lowly San Diego Padres. 

Martinez, on the other hand, is pounding lefties to the tune of a .474 average and 1.661 OPS.

Here's how an unnamed National League general manager summarized it, per ESPN.com's Jerry Crasnick:

"J.D. Martinez is a pretty damn good hitter. I understand the idea of not giving up too much for mid-tier rentals. But when you have the top rentals—and I think J.D. Martinez is the top rental bat—giving up two or three names isn't that crazy. [Executive vice president] Mike Hazen is a very smart guy. If he and his staff felt like the value is there, I'm certain that it is."

That would be the same Mike Hazen who has helped initiate a culture change in the desert and turned the D-backs from one of 2016's biggest busts into an October contender. 

A run at the division-leading Los Angeles Dodgers, who are 10.5 games ahead, is a long shot but not an impossibility.

Sarah Sachs/Arizona Diamondbacks/Getty Images

With Martinez in the fold, though, Arizona can set its sights squarely on the top wild-card berth. At 53-39, they presently boast that position by 1.5 games over the Colorado Rockies.

Hitting isn't everything. Fortunately, the Diamondbacks check in second in the game in team ERA. A rotation fronted by a resurgent Zack Greinke and hard-throwing Robbie Ray is ready for prime time. Greinke, in particular, is chambered for a possible wild-card play-in.

There are questions surrounding closer Fernando Rodney, but right-hander Archie Bradley is among the best relievers throwing, and the club could make another trade to augment the bullpen.

Put simply: The Diamondbacks were one of the most complete teams before the Martinez swap. They could have stood pat and been regarded as a solid sleeper pick to push the Dodgers and Washington Nationals in the NL.

Now, the sleeper business is over. Every potential playoff opponent should be wide awake.

These D-backs are revving their engine, and the sound is loud and clear.

All statistics current as of Tuesday and courtesy of MLB.com and Baseball-Reference.com unless otherwise noted.