In Saturday's blowout win over the Giants, seldom-used relievers like Ryan Cook, Zach Duke and Alberto Castillo got looks.
"We got the chance to watch some guys throw [Saturday] and hopefully we'll get to see some more guys throw [Sunday]," manager Kirk Gibson said. "There will be tough decisions, but we'll have to make them."
National League teams usually carry 12 pitchers during the regular season but only 11 during the postseason.
"Nothing is in stone," Gibson said. "You would think it would probably be 11, but that's certainly not in stone. It depends on a lot of stuff."