RHP Jameson Taillon: Added to the 40-man roster as protection from December's Rule 5 Draft, the Bucs' No. 2 ranked prospect is still working his way back from Tommy John surgery in early April.
RHP Nick Kingham: The Pirates' No. 5 prospect, he is closest to arriving in terms of Triple-A experience, having wound up the 2014 season with 14 starts and 88 innings in Indianapolis (5-4, 3.58 ERA).
INF Alen Hanson: The Pirates will evaluate his ability to play second base -- after his 94 errors in 295 Minor League games at short the last three seasons. Despite those defensive issues, his No. 6 ranking among Pittsburgh prospects attests to his overall skill set.
C Elias Diaz: Perhaps nothing intrigues big league brass more about this camp than getting its first extensive in-person look at this fast-rising talent. This 24-year-old Venezuelan wasn't even on the radar a year ago, but that all changed with lavish reports on his defense during a .328 All-Star season with Double-A Altoona.
OF Willy Garcia: Clint Hurdle's eyes sparkle when discussing this 22-year-old Dominican, the Pirates' No. 13-ranked prospect. Garcia slashed .271/.311/.478 last season in Altoona; in his age-22 season, Starling Marte was still playing Rookie League ball.
RHP John Holdzkom: He may be 27, but a Major League resume of nine innings qualifies you as a prospect. He dropped quite a teaser with his September splash, and the Bucs are eager to see if the magic has staying power.
RHP Tyler Glasnow: He's getting the Gerrit Cole-Taillon treatment. Both were given their first tastes of big league camp as non-roster invitees, and the Pirates' latest No. 1 prospect will also be around merely to be introduced to the atmosphere. The big question is whether the Pirates might have him skip Double-A and start the season in Indianapolis, after his 21-8, 1.94 slate in 2013-14 at the Class A and Class Advanced A levels.
RHP Adrian Sampson: Being the big winner in Altoona (10-5, with a 2.55 ERA) earned the 6-foot-3, 200-pound righty a No. 19 ranking among Pirates prospects, and he is definitely ticketed for Triple-A. He could be the 2015 version of the 2013 Brandon Cumpton -- come to the Bucs' midseason aid as a long reliever/spot starter.
1B Stetson Allie: "Babe" Allie has struck 42 homers in his first two seasons since abandoning pitching, with an .800-plus OPS, including 21 and .801 in Altoona last season. The Pirates invited him to camp to see whether he is a legitimate future option at first base. He was drafted out of high school in 2010, so will turn only 24 on March 13.