"Because I don't have to yet," Mattingly said.
Mattingly did say Pederson has done everything in Spring Training that the club wanted to see. The rookie is hitting .375 with nine RBIs and a 1.120 OPS. Andre Ethier, Pederson's primary competition, has been solid as well, hitting .333 with nine RBIs and a .904 OPS.
Other than repeating what he already said about Jimmy Rollins leading off, Mattingly said he hasn't settled on a batting order and was still undecided whether to bat Yasiel Puig and Adrian Gonzalez second and third or third and fourth.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.