Quintana (thumb) is on track to begin throwing later this week, Maddie Lee of NBC Sports Chicago reports.
Quintana underwent microscopic surgery on his left thumb in early July and this will be his first time throwing since then. He has been able to continue with a workout program in the meantime. The lefty seems likely to miss at least one turn through the rotation, which figures to open the door for Alec Mills to step in as a starter.