Jon Paul Morosi reports the Pirates are interested in young Diamondbacks star outfielder Justin Upton.

Major-league sources told FOXSports.com the Pirates have had preliminary trade discussions regarding two power-hitting outfielders, San Diego’s Carlos Quentin and Arizona’s Justin Upton. Talent evaluators from those two clubs have scouted Pittsburgh’s minor-league affiliates in recent days, as the teams prepare preference lists of prospects they want in the potential deals.

If the Pirates were to trade for Upton, it would be a blockbuster of epic proportions. Upton is having a disappointing year, but he's still only 24 (a year younger than Andrew McCutchen), has several good-to-great seasons on his resume, and was once the first overall pick of the draft. he's also signed through 2015. The Diamondbacks will ask for a king's ransom for him. And when they do, the Pirates should strongly consider paying it. I would imagine any deal would start with one of the Bucs' top two pitching prospects, either Gerrit Cole or Jameson Taillon, and probably also include a couple other very good prospects.

For more on the Pirates, check out Bucs Dugout. For more on the Diamondbacks, check out AZ Snake Pit.