"I really didn't want him sitting around waiting," Giants manager Bruce Bochy said, explaining why Johnson will launch the twin bill against Nationals right-hander Jordan Zimmermann. San Francisco right-hander Matt Cain will oppose left-hander Ross Detwiler in the second game.
Wednesday's delay, which lasted three hours and 41 minutes, was prolonged not only by persistent thunderstorms, but also by the knowledge that today's weather forecast is anything but promising. That factor fed a sense of urgency among umpires and officials from both clubs to get in Wednesday's game.
Ultimately, it was generally agreed that the field was unplayable, particularly as the outfield began to resemble a map of Minnesota -- the land of 10,000 lakes.
"Under no circumstances do you want to get somebody hurt in the process," said Giants president Larry Baer, who joined the consultations.
Johnson, who has experienced such inconveniences during 22 seasons in the Major Leagues, remained ready during the delay.
"He was just trying to find out the updates in the weather and the possible starting time," Bochy said.
Giants right fielder Randy Winn said Johnson and his other teammates did relatively little during the delay and that this long night of waiting didn't differ much from any other, though they wanted to help their pitcher reach a milestone.
"You know about it, but it was like any other rain delay," Winn said. "It's like hurry up and wait."
Due to a pair of scheduled off-days, Johnson already was due to pitch on six days' rest, two more than usual. Now he must pitch on seven days' rest, almost twice as much as the four he'd typically receive. The 6-foot-10 left-hander wasn't around afterward to comment, though Bochy said, "I'm sure he's anxious to pitch."
Past performances suggest that the excess rest shouldn't corrode Johnson's skills too much. In 67 career starts with six or more days' rest, Johnson's 28-22 with a 3.11 ERA. At age 45, he might benefit from the bonus off-days.
Nevertheless, Bochy admitted that remaining idle Wednesday was "a little bit of a letdown. It's a long day to do nothing. We didn't get on the field. We're excited about Randy reaching this milestone."
So, too, must be many fans in Arizona. Assuming that Johnson would receive four days' rest before his next start, he'd pitch again Tuesday in Phoenix against the Diamondbacks -- with whom he won four of his five Cy Young Awards from 1999-2004 before joining them again in 2007-08. One might imagine that thousands of D-backs fans are rooting for Johnson to absorb a no-decision or even a loss against Washington so his bid for No. 300 will remain alive during next week's series at Chase Field.
But Bochy dismissed that as "conjecture," perhaps because the Giants must find a starter for Monday's series finale at Florida -- unless Johnson or Cain works on three days' rest, one fewer than usual.
The Nationals serve as a fitting opponent for Johnson, who started his professional career with that franchise when it was known as the Montreal Expos.
Johnson's trying to become just the sixth left-hander to achieve the 300 milestone and the fifth pitcher in the last 50 years to do it on his first attempt, joining Warren Spahn, Steve Carlton, Gaylord Perry and Tom Seaver.
According to the Elias Sports Bureau, Johnson would become the second-oldest pitcher to reach the 300 mark -- behind only Phil Niekro, who achieved the feat when he was 46 years and 188 days old on Oct. 6, 1985. Johnson is 45 years and 267 days old.
Johnson would be the seventh pitcher in Giants history to win 300 games while pitching for the franchise at some point in his career. He'd also be the fourth to hit that plateau as a Giant, joining Tim Keefe, Mickey Welch and Christy Mathewson.
Don't bring such facts to Zimmermann, the Nationals' promising rookie. He said that he's going to avoid dwelling on confronting Johnson and is more worried about the Giants hitters.
"It's like another game to me," Zimmermann said. "I'm facing the hitters. I'm not really facing [Johnson]. I won't be trying to learn things [from Johnson]. I'll be going out there and pitch a ballgame and try to get a win."
In some ways, today's 18 innings of baseball -- weather permitting -- won't seem as ponderous as Wednesday's plenty of nothing.
"I felt like I just played a game," Nationals third baseman Ryan Zimmerman said.