Redding broke his left wrist in a qualifying crash on Saturday.
Following surgery, his Marc VDS team announced that Redding, who has led the points for most of the year, was now set to miss next week's Motegi event and would return for season finale at Valencia at the earliest.
In Redding's absence, Espargaro took victory in the shortened Phillip Island race, putting him into a 16-point lead.
His situation was boosted further by his Pons team-mate Tito Rabat, a championship outsider, making a mid-race mistake and finishing only eighth.
- Sports & Recreation