Kershaw has been on the disabled list since suffering a strained teres major muscle on the left side of his back in his Opening Night win in Australia. It is Kershaw's first time on the disabled list.
On Wednesday, Mattingly said Kershaw would need at least a second rehab start before being activated. Kershaw will probably lobby to return immediately if Friday night goes well. He is expected to make 55-65 pitches and his next day to pitch would be Wednesday. The Dodgers have a travel day on Monday.
Kershaw's spot in the rotation has been filled by Paul Maholm, who is scheduled to pitch Saturday and again next Friday.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.