Marte is one of the few minor league free agents the Pirates have added this off-season.
One of the less attention-grabbing rituals of the baseball off-season is the signing of minor league free agents. Most or all of the major league teams will sign a significant number of free agents, most of whom will end up in AAA. Teams use their AAA rosters partly as the equivalent of taxi squads, to maintain depth in the event of injuries or other problems in the majors.
Of course, if all your AAA players were obtained as minor league free agents, that's a bad sign. Not only does it show you have no prospects at that level, it means your drafting and international scouting has been so bad that even the players who aren't great prospects are dropping out at the lower levels of your farm syst...
Wilbur Miller joined the site in July 2010. He has long been known for his excellent Player Profiles, which he brought to the site in February 2011, combining them with the existing Pirates Prospects Player Pages. Wilbur maintains the player pages section of the site, and provides regular articles to the main portion of the site, including a weekly Prospects Trend piece, featuring the best and worst prospects from the previous week.