Reds manager David Bell said Tuesday that Williamson is considering undergoing season-ending surgery to remove a lesion from his left shoulder, Mark Sheldon of MLB.com reports.
Williamson has been out all season with shoulder problems and was recently pulled off a rehab assignment because of recurring discomfort. While the lefty would be done for the season if he opts to go under the knife, it's unclear what a timetable would look like if he decides against surgery.