Reyes will undergo Tommy John surgery next week, Fabian Ardaya of The Athletic reports.
Reyes was diagnosed with a UCL sprain in early March, and it turns out that the injury is bad enough to require surgery. A typical recovery timeline would see Reyes shut down until the middle of next season. At that point, he'll be a 29-year-old coming off major surgery with just 26 big-league innings to his name.