Manager Torey Lovullo said Friday that Montgomery (knee) will begin throwing off flat ground Saturday, Jesse Friedman of GoPHNX.com reports.
Lovullo noted that Montgomery is still dealing with a bit of inflammation in his right knee, but the team believes he'll be in good enough condition to throw. Assuming all goes well Saturday, the 31-year-old southpaw will likely be given the green light to begin throwing off a mound within the next several days.