It was first reported, I believe, by Joe Strauss last night on Twitter. The Cardinals plan to call up short stop Ryan Jackson from Memphis to replace Tyler Greene on the active roster.
Jackson, 24, was drafted by the Cardinals in the 5th round of the 2009 MLB Draft out of the University of Miami. Jackson has shown a good glove in his time in the minor leagues. He currently has a .971 fielding percentage, pretty similar to the one that Rafael Furcal has put up in St. Louis.