Luke Weaver was diagnosed with a Flexor Pronator Strain AND a Mild UCL Sprain
He is completely shut down from throwing and the team will pursue a “conservative” course, meaning he will not have surgery. Torey Lovullo refused to give any time table for when Luke might begin throwing again, as he felt that would be unfair to Luke. Some basic research on Flexor Pronator Strain indicates that rest required for healing can be anywhere from 2 to 6 weeks. THIS VIDEO contains a pretty good overview of the injury.
This injury, coupled with the “Mild” UCL Sprain would seem to indicate that it will be at least 4 weeks before Weaver is able to resume throwing.