Assad will be called up to start the first game of Tuesday's doubleheader against the Cardinals, Mike McGraw of the Chicago Daily Herald reports.
Assad was promoted to Triple-A Iowa at the beginning of July, and he's posted a 2.95 ERA and 1.05 WHIP in 36.2 innings over eight appearances (seven starts) at the Triple-A level. The Cubs' starting rotation is currently banged up, so it's possible that Assad makes more than one turn through the rotation if he performs well Tuesday.