There was some mild confusion when the Cubs released the first iteration of their 60-man player pool, largely because they only included 50 names. Though a few top prospects like catcher Miguel Amaya, lefty pitcher Brailyn Marquez, outfielder Brennen Davis, and third baseman Chris Morel were among that group, many others were conspicuously left off.
The main reason the Cubs only listed 50 players was to give themselves a little flexibility throughout the next three weeks. They are probably going to be shuffling the major league roster to some extent, so naming a full 60 players to the pool would have meant making corresponding transactions to clear space.