McCullers (foot) played catch Saturday and is scheduled to do so again Sunday, Matt Kawahara of the Houston Chronicle reports.
Manager Joe Espada relayed that McCullers could start throwing off a mound Monday as long as he doesn't suffer any setbacks. McCullers landed on the 15-day injured list this past Monday due to a right foot sprain. How his foot reacts to increased work will give the Astros a better sense of when McCullers can embark on a rehab assignment, if one is needed.