Pirates net three players in two trades

The Pirates' apparent modus operandi as next week's Winter Meetings approach: acquire players whose Minor League success has not transferred over to the Majors, at least not yet.

In a pair of trades announced by the club Wednesday, Pittsburgh acquired first baseman Clint Robinson and right-handed pitcher Vin Mazzaro from Kansas City and another right-hander, Zach Stewart, from Boston.

Robinson, a 25th-round draftee in 2007, batted .308 in his six seasons in the Royals organization. The 6-foot-5, 240-pound left-handed hitter also averaged 18 home runs per year but, with first baseman Eric Hosmer and designated hitter Billy Butler entrenched in Kansas City, was blocked from consistent playing time in the bigs. Robinson has the least MLB service time of the three new Pirates, having accumulated his first four big league at-bats spread over four games last June -- three at PNC Park.

"Want to thank [general manager] Dayton Moore and the entire #Royals org. for the past six years! Great people/teammates and a great org.! Will miss all of u!" Robinson (@ClintR1b25) wrote in a Tweet today.

Like Robinson, Mazzaro was designated for assignment by the Royals on Nov. 20, a procedural move that removed both players from the club's 40-man roster. The 26-year-old finished his second up-and-down season after the A's sent him to the Royals in a deal involving Major League outfielder David DeJesus on Nov. 10, 2010. Mazzaro compiled a 3.63 ERA in 22 games (eight starts) at Triple-A Omaha, but his ERA increased by two runs, to 5.73, in 18 MLB appearances.

To obtain the Royals' pair, the Pirates parted with left-handed pitcher Luis Rico and right-hander Luis Santos. Rico, a native of Venezuela, turns 19 on Thursday, while Santos, who hails from the Dominican Republic, will be 22 by Opening Day. Both hurlers competed in the Dominican Summer League this year and have yet to make their stateside debuts.

A player to be named later was the cost for Red Sox hurler Stewart. Like Mazzaro, Stewart's performance in the Majors last season paled compared to his results in the Minors. The 26-year-old, another 40-man roster casualty in advance of the Dec. 6 Rule 5 Draft, fashioned a 3.94 ERA in 11 starts for Triple-A Pawtucket but recorded an 8.58 ERA in 20 games (three starts) in Boston.