1B Travis Ishikawa
LHP Daniel Schlereth
LHP Adam Wilk
LHP Brandon Mann
RHP Elvin Ramirez
(The Pirates' tweets also mention UT Michael Martinez, who we already knew about.)
It's nice to have McPherson back, although his elbow injury clearly remains enough of a concern that no one wanted to use a roster spot on him.
Of the remaining players, Ishikawa and Schlereth are the headliners. Ishikawa, who played several years with the Giants, is a lefty first baseman who doesn't hit well for the position but plays passable defense. Clearly, he isn't a solution to the Pirates' vacancy at first, but it's good to have him as depth. Schlereth is a former first-round pick who has posted high strikeout rates throughout the minor leagues, but he only has a total of a little over 200 innings pitched between the minors and the majors, due to injuries. He lost a bunch of velocity after a shoulder injury in 2012 and didn't pitch much at all last year, so we'll see if he's ready to go in spring training.
Wilk, who just turned 26, posted a good Triple-A season as a starter in the Tigers organization in 2012. In 2013, he went to Korea, but he struggled there, and his season apparently ended early with a shoulder injury. Mann didn't receive a spring-training invite and didn't pitch in 2013. He played in Japan in 2011 and 2012. Ramirez is a hard-throwing reliever who has control issues; he pitched in the Angels system in 2013.