Pirates Add Starting Depth in Stewart, Mazzaro

Somewhat lost in the shuffle of some bigger moves that took place this week (including the team’s surprising free agent signing of Russell Martin), the Pittsburgh Pirates completed a pair of minor trades on Wednesday afternoon that ultimately resulted in adding some much-needed pitching depth to the organization. The Pirates added right-handers Vin Mazzaro and Zach Stewart in the two deals, along with first baseman Clint Robinson, for what was a minimal cost overall.

Newly acquired right-hander Zach Stewart game up an MLB-worst 3.5 HR/9 last season. (Image Credit: Kirby Lee/Image of Sport-US PRESSWIRE)

Stewart’s had the most success of the group at the minor league level, though that success has yet to translate to the Major Leagues. He’s pitched 103.0 innings over the past two seasons, seeing time with the Toronto Blue Jays, Chicago White Sox, and Boston Red Sox. He’s 3-10 with a 6.82 ERA in that span, allowing a concerning 2.2 HR/9. This is the fourth time that Stewart has been traded in his career, a sign that teams clearly think highly of his potential despite the fact that he’s yet to see that success materialize.

Mazzaro is coming off of his second up-and-down season for the Kansas City Royals, after joining the team in a trade from Oakland prior to the 2011 season. Over parts of the past four seasons, the 26 year old is a combined 15-21 with a 5.22 ERA over 286.0 innings (66 appearances, 45 starts). Numerous factors have led to Mazzaro’s lack of success to date, though namely it’s been the result of a lack of control (3.9 BB/9, 10.7 H/9, 1.622 WHIP) and a severe dip in his strikeout rate from his minor league numbers (5.5 K/9 vs. 7.1 K/9 in the minors).

As for Robinson, the 27 year old has batted .308/.382/.520 across 2,875 plate appearances over the past six seasons in the minors. He’s spent the past two years at Triple-A, posting respectable numbers including an average of 18 HR and 83 RBI each year. Robinson did make his MLB Debut this past season for the Royals, seeing four plate appearances this past June (three of which came at Pittsburgh’s PNC Park). While he’s seen some success in the minors, most scouts question whether his abilities will translate in the Major Leagues. Robinson’s opportunity was likely not going to come in Kansas City, considering the team already has Eric Hosmer and Billy Butler entrenched on the roster.

Neither Stewart nor Mazzaro are guaranteed a spot on the Pirates roster, but both will likely be given a chance during Spring Training to at least place themselves firmly on the team’s depth charts. Robinson’s fate is just as uncertain.

Pittsburgh sent a pair of pitchers to Kansas City in exchange for Mazzaro and Robinson, neither of whom have yet to pitch stateside as of yet. Left-hander Luis Rico, 19, is 1-2 with a 5.29 ERA over 49.1 innings the past two summers between the Venezuelan and Dominican Summer Leagues. Right-hander Luis Santos, 21, has gone 8-4 with a 2.51 ERA over 86.0 innings in the DSL over the same span.

Boston will receive a player to be named later in return for Stewart.