Ryu, meanwhile, won't pitch in a Spring Training game, Roberts said, which is no surprise considering the slow pace of his recovery from last year's shoulder surgery. Ryu went 17 days between throwing off a mound. He did it Monday and might again on Thursday, but he is nowhere close to being game ready.
"His timetable has been pushed back," said Roberts. "I'm not going to put a date on when he'll come back, but for me, [May] is unrealistic at this point. It's aggressive. You never know how things change."
Roberts added that because Ryu has never had shoulder surgery before, "there is a bit of hesitancy when some of the pain is coming back, and there's something to that as well."
With Ryu out, Roberts acknowledged that he might not have one fifth starter, but possibly two or more who can be shuffled up and down from Triple-A with creative roster manipulation. The most likely leading candidates are Mike Bolsinger and Brandon Beachy, but Roberts has said Zach Lee and Julio Urias are also in the conversation.
Roberts' explanation on the Ethier revelation was simple:
"He gets on base."
Moving the 33-year-old Ethier to the top of the order is also a concession to the lack of a prototypical leadoff hitter on the Dodgers' roster, ironic because that's exactly what Roberts was as a player.
Instead, Roberts said he will pick Ethier to lead off when the pitching matchup entices him to give the outfielder a chance for an extra at-bat against a particular pitcher.
That as a criteria opens up the top spot to virtually any Dodgers hitter, from Howie Kendrick or Chase Utley to Joc Pederson or Yasiel Puig to Kiké Hernandez or a healthy Corey Seager.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.