Though primarily a center fielder, Marte will likely become Pittsburgh's left fielder -- center is manned by National League MVP candidate Andrew McCutchen. The Pirates have been platooning Alex Presley and Drew Sutton in left field recently.
Marte, 23, was having a fine season for Indianapolis. In 98 games, he hit .286 with 20 doubles, 13 triples, 12 home runs, 61 RBI and 21 stolen bases. He won the Eastern League batting title last season with a .332 average for Double-A Altoona.
Marte has never played in the major leagues. Scout.com ranked Marte as the 87th-best prospect in the game earlier this year.