"I'm just looking for a performance," Baker said. "Just give us all that you got, and then we'll take it from there."
The Dodgers, who also debated multiple Game 4 pitching scenarios, will counter with Clayton Kershaw on short rest.
Ross hasn't pitched much since returning from a two-month bout with right shoulder inflammation in September, starting three times but maxing out at four innings and 90 pitches. That outing was his last of the regular season, almost two full weeks ago.
Compare that to Lopez, who hasn't started a game since Sept. 4. Appearing exclusively out of the bullpen over the season's final four weeks, Lopez threw as many as 85 pitches in an outing -- though that came way back on Sept. 24. Lopez finished 5-3 with a 4.91 ERA overall as a rookie, but was 2-3 with a 5.52 ERA as a starter.
The Dodgers tagged Lopez for six runs in 4 2/3 innings back on July 19, while Ross held them to two runs over 6 1/3 innings on June 22.
Considering their bullpen's current form -- 12 1/3 shutout innings so far this postseason -- the Nationals don't need length out of Ross so much as effectiveness. Essentially, the Nats need the type of performance that Ross provided so regularly prior to his shoulder injury, going 7-4 with a 3.49 ERA over his first 16 starts. Relying heavily on a mid-80s slider that generated a 22-percent whiff rate (10th in baseball among the 73 pitchers who threw at least 400 sliders during the regular season), Ross, at age 23, established himself as a rising star.
Part of the choice to start him over Lopez, Baker said, was the fact that he is also more formidable as a hitter. Ross' .244 batting average ranked fifth in baseball this season among pitchers with at least 40 plate appearances.
"One thing about Joe, if his spot's coming up and he's still strong, and depending on the score, what helps is that I don't have to hit for him," Baker said. "He's one of the best hitters I have. So that went into our decision, too."
But it's mostly Ross' arm that can deliver the Nationals to a place they've never been before -- their first postseason series victory since the franchise moved to Washington.
"We're not afraid of this," Dodgers manager Dave Roberts said. "It's been a long season. It's been a lot of highs and lows. But I know that there's no quit in our guys. So we'll be ready [Tuesday] to win a baseball game, I can promise you that."