Dodgers in midseason form in the rotation flexibility department

Baseball knows well how the “best-laid plans” routine turns out. You plan in pencil in this game.

The Dodgers, though, would like to have gotten through their first series on U.S. soil without facing the possibility of turning their rotation upside down.

Ace Clayton Kershaw is out with a sore back. Hyun-Jin Ryu could be out with a sore toe.

Now their three-game series in San Diego could feature starting pitchers Dan Haren, Zack Greinke and Paul Maholm. And they might want to place Greinke in bubble wrap.

Kershaw has officially been scratched from Sunday’s mainland opener against the Padres.

“We’ll have all our pitchers ready Sunday,” said Dodgers Manager Don Mattingly.

Ryu would be the first Sunday option, but it’s uncertain when he’ll be ready. He injured the nail on his right big toe Sunday in Australia running into the third base bag. It tore the nail. On Tuesday he saw a podiatrist and said about half of it was cut off.

“They said it looked really good,” Ryu said.

He went through pitching motions in the bullpen Wednesday -- but without throwing the ball -- and reported improvement with the toe.

“He felt pretty good in the bullpen,” Mattingly said. “We’ll see how that goes tomorrow. And that’s when we’ll make a decision on Sunday. We’re a little bit day-to-day with Hyun-Jin.”

Whether or not Haren is forced into the nationally televised opener on Sunday, following Monday’s off-day, Greinke will start Tuesday. Greinke is coming off a spring calf injury and is first scheduled to start Thursday’s exhibition game against the Angels.

Wednesday could see Haren, Maholm or Ryu start. It’s the undefeated Dodgers’ first three-game series of the season and they’re already in serious play-it-by-ear mode.

“We’re going to be flexible,” Mattingly said.

Early practice, because, no doubt, more is to come. Plan on it.