Quintana (hamstring) threw a successful 21-pitch bullpen session Sunday and said he could re-enter Colorado's rotation as early as Wednesday at Houston, Thomas Harding of MLB.com reports.
The veteran left-hander landed on the shelf due to a hamstring strain after his season debut March 29, but it appears he'll be able to rejoin the Rockies' rotation without a rehab assignment. The team has yet to announce its pitching plans for this week, but Quintana should be expected to take the mound Wednesday or shortly thereafter.