The DBacks are listening to offers for Justin Upton, and with most NY-based reports indicating the Yankees will let Nick Swisher walk at the end of the season due to the Steinbrenner Cap, you have to wonder — would it make sense for the Yankees to make a play for Upton in a longer-term planning move?

The former #1 draft pick is still only 24 years old and is under contract through 2015. For luxury tax purposes, which is what Big Hal is so concerned about, Upton’s average annual value (AAV) is a touch over $8.5 million. That’s a bargain for what Upton has already accomplished in his career.

Since 2009 (when he was 21 years old), Upton has put up the following numbers:

2164 PA, .285/.363/.488, .367 wOBA, 123 wRC+, 123 OPS+, 15.4 WAR

Plus, according to UZR, TotalZone, and Fangraphs’ Fans Scouting Report, he’s a better than average defensive right-fielder — not anything to write home about, but still slightly better than your average bear.

Combine all these numbers with the fact that he’s still 3-4 years away from a baseball player’s typical peak, and you have to question why Arizona has attempted to trade him on multiple occasions over the past couple years. What about him do they find unappealing?

Well, this year’s there’s plenty to find unappealing. He’s having the worst year of his young career, hitting .273/.353/.401. The biggest problem is with his power. A career .201 ISO hitter, he’s now slugging at a .128 ISO.

And when looking deeper at his numbers, there’s really no case to be made that he’s experienced bad luck. It’s a legitimate decline in power, possibly stemming from a thumb injury early in the season. In a recent Sports Illustrated article, one scout stated the following about Upton:

“He had a thumb injury [in April] slow him down, but I think the shoulder [which he injured in 2010] is bothering him. He’s just not hitting through the ball.”

“I’m not sure he’s the perennial MVP caliber player we all thought he’d be. But a player with that talent, under control for three more seasons at a pretty good price — he’d be a game changer for a team.”

So do you just chalk this season up as just a lousy one in an otherwise very good young career? After all, he could turn it around in the second half, and again, he’s only 24. Or, is his first half a legitimate concern?

Even if the Yankees were interested, would they have the pieces? According to local Arizona media, here’s what the DBacks are looking for:

Club sources say they would seek a third baseman, shortstop or frontline starting pitcher as the centerpiece of an Upton deal; they believe he could command a package of perhaps three players.

“Kevin’s not trading for some shining day in the future,” a rival executive said. “Upton may go on to have a Hall of Fame career, but I bet you the deal he makes will help the 2012 and 2013 Diamondbacks. That’s what he does well. What he won’t do is a deal that will shoot him in the foot.”

If the Diamondbacks are looking for impact players that could contribute to the big club in the near-term, the Yankees will fall short here. The most prized commodities in the Yankees’ system are in the lower levels of the minors. Kids in the upper levels who at one point could fetch a pretty penny have either blown up (Betances) or been hurt (Banuelos, Romine). That’s not to say the Yankees don’t have usable pieces in AAA & AA, or that there won’t be prospects who break out (Vidal Nuno at AA). However, there’s certain to be substantial competition for Upton, and probably from organizations that are more top-heavy at the higher levels.

Still, it’s all interesting to think about.