The Pittsburgh Pirates are in first place. Clearly, they intend to stay there.

Major-league sources told 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.

It seems unlikely the Pirates would acquire both Quentin and Upton, but they have a strong desire to upgrade their lineup by landing one of them. Pirates center fielder Andrew McCutchen is putting together an MVP season in the No. 3 spot, but he will see fewer pitches to hit in the second half unless general manager Neal Huntington adds a cleanup hitter. Garrett Jones and Casey McGehee have batted fourth for the Pirates in recent days.

Quentin would come at a lower prospect price, because he's eligible for free agency after this season. Upton would command a larger package, since he's under contract through 2015.

Upton, who finished fourth in the MVP balloting last year, would be the bigger splash for an organization seeking to re-establish itself. Upton's relationship with the Arizona franchise has soured recently amid criticism from owner Ken Kendrick, but he's highly regarded within the industry. A change of scenery may be the best thing for Upton. If he lands in Pittsburgh, he would combine with McCutchen to give the Pirates their best collection of star talent since the departure of Barry Bonds.

The Pirates, who invested large sums of money in the draft over the past several years, have the prospect depth to consummate a deal for either Upton or Quentin. The question is how willing Huntington will be to part with the necessary pieces.

Two Pirates pitching prospects — right-handers Gerrit Cole and Jameson Taillon — were selected for Sunday's All-Star Futures Game in Kansas City. The Pirates are said to be more reluctant to trade Cole than Taillon, in part because Cole is closer to the majors.

The Diamondbacks are in the midst of a disappointing season after winning the National League West last year. Officials of the club believe they can compete again next year, so general manager Kevin Towers likely would focus on acquiring prospects who are close to the majors. Pirates outfield prospect Starling Marte, who has an .846 OPS as a 23-year-old at Class AAA, is one potential fit. But it would take more than Marte to get Upton. Upton, after all, is only 24 and has been in the majors for all or part of six seasons.