Greinke flew home to Los Angeles on Thursday morning in order to be with his wife, Emily, for the expected birth of their first child.
Mattingly said the team is hopeful that Greinke can return to New York in time to pitch on Saturday or Sunday.
Greinke is currently on a streak of having thrown 43 2/3 scoreless innings that dates back to before the All-Star break. The 31-year-old is 9–2 with a National League-best 1.30 ERA to go along with a 0.822 WHIP this season.
In addition to Friday, the Dodgers also currently have an open rotation slot for Saturday. Sunday's scheduled starter, Brett Anderson, left his start on Tuesday with an irritated left Achilles tendon.
Los Angeles entered Thursday in first in the NL West with a 54–42 record.
- Molly Geary