The White Sox will be sending RHP Chris Bassit, LHSP Charlie Leesman, LHP Stephen McCray, RHP Kevin Vance, INF Micah Johnson and SS Marcus Semien to play in this year's Arizona Fall League. White Sox prospects will play for the Glendale Desert Dogs, along with prospects from the Dodgers, Marlins, Reds and Twins.
The Arizona Fall League runs from October 8 through November 14. It is considered to be a "finishing school" for prospects, though (as one can tell from the White Sox contribution) it is normally light on pitching prospects because most notable pitchers have piled up enough innings - though pitchers who missed time, such as Leesman, are prevalent.
This roster suggests that Leesman and Semien will not be called up in September, However, AFL rosters are subject to change and we can expect some addition and potentially some subtraction before (and even during) the season.
South Side Sox will, of course, have daily coverage of the AFL.