CHICAGO — This was going to be Stephen Strasburg’s moment of glory.

The time he took the ball, thanks to Tuesday night’s rainout in Game 4 at Wrigley Field, and saved the Washington Nationals’ season.

It would be his opportunity to be a hero in Washington, erasing those painful memories of 2012 when he was shut down for the playoffs, perhaps ruining the Nationals’ best chance to win a World Series.

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The Nationals were all set to pitch him Wednesday in Game 4 at 4:08 p.m. ET (TBS) at Wrigley Field, trailing 2-1 to the Chicago Cubs, only for Strasburg to decline.

He told them he’s under the weather.

He informed the Nationals’ staff that he ran a half-mile Tuesday afternoon, was wheezing during his run and simply isn’t prepared to start Wednesday, even though he’d be on regular rest, according to a person with direct knowledge of the Nationals' pitching plans.

The person spoke to USA TODAY Sports on condition of anonymity because he was not authorized to speak publicly about internal deliberations.

So they are going back to Tanner Roark, while Strasburg waits to see if there even is a Game 5 on Thursday at Nationals Park.

Nationals manager Dusty Baker tried to cover for Strasburg at their press conference, saying that Strasburg threw a bullpen session Tuesday and was simply unavailable.

Only Strasburg actually threw his bullpen session Monday.

He didn’t throw a pitch Tuesday.

And decided, apparently, that he couldn’t go in Game 4.

Unbelievable.

This was a golden chance for the Nationals to flip the script, stealing the Cubs’ thunder from a year ago when they used a 17-minute rain delay in Cleveland to stem the Indians' comeback, reverse course and win Game 7 of the World Series.

This would be the rainout that saved the Nationals’ season, going with the guy who dominated the Cubs in Game 1, flirting with a no-hitter until the sixth inning and giving up just three hits and two unearned runs and striking out 10 Cubs in seven innings.

The same Strasburg who went 5-1 with a 0.84 ERA, yielding a .171 opponent’s batting average in his final eight regular-season starts.

The same Strasburg who finished with a career-best 2.52 ERA, yielding a league-low .317 slugging percentage and producing a franchise-best 35-inning scoreless streak.

Uh-uh. Strasburg is famously committed to his between-starts routine, even, as we know now, if it's an elimination game at hand.

“He’s under the weather,’’ Baker said, “like a lot of my team is.’’

Can he at least pitch out of the bullpen in Wednesday’s game, if necessary, knowing the season is on the line?

“I don't know, man,’’ Baker said. “I ain't even thinking about that to tell you the truth. I'm thinking Tanner's going to do his thing.’’

Roark, 13-11 with a 4.67 ERA, is a veteran pitcher with postseason experience. It will be the fourth postseason game of his career and his second start. He also has a 2-0 record and 1.56 ERA in his last three starts at Wrigley Field.

“We have full confidence in Tanner,’’ Baker said.

Yet he is not Stephen Strasburg.

He is not a $175 million pitcher.

He is not one of the faces of the franchise.

There’s a reason why he was the Nationals’ fourth choice to start a playoff game.

Maybe everything still works out for the Nationals, Roark wins and Strasburg closes it out in Game 5.

But maybe it backfires, the Nationals lose, Strasburg doesn’t throw another pitch until spring training and the Nats spend another winter being mocked for not having won a postseason series, with Cubs board member Todd Ricketts calling them chokers during their White House visit.

If you’re Strasburg, you better hope the Nationals win, you get a chance to close out the Cubs and be the man everyone envisioned when he was the No. 1 pick in 2009 Draft.

Then again, even if Roark pitches a beauty, it won’t make a bit of difference if the Nationals don’t start hitting.

They are hitting just .121 this NLDS with a .200 on-base percentage and .231 slugging percentage. They’ve scored an earned run in just two of 27 innings. The Cubs’ starting rotation is not only yielding a 0.48 ERA but has been even more dominant the longer they’re in the game.

The Cubs’ starters, when facing the Nats’ lineup a second and third time, have yielded just one hit in 38 at-bats, a mind-blowing .026 batting average.

Baker shuffled his lineup Tuesday in hopes of generating offense and will keep it the same Wednesday. He kept Trea Turner in the leadoff spot, despite being hitless this series, and put Jayson Werth in the No. 2 spot while batting Bryce Harper third.

“First time we've had that lineup in months since Harp got hurt," Baker says. "Feels pretty good.

“I feel very good about our chances.’’

Only he’d be feeling a whole lot better if you-know-who were pitching Wednesday.

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