Manager Oliver Marmol said Saturday that Reyes (shoulder) will be shut down from throwing for at least four weeks, John Denton of MLB.com reports.
Reyes received a stem-cell injection in his throwing shoulder Friday and will have about a month to rest before starting a throwing program. The 27-year-old is expected to be unavailable for game action until at least late May, while Giovanny Gallegos and Genesis Cabrera should open the regular season as the favorites for save opportunities.