Kevin C. Cox/Getty Images

Nationals left-handed starter Ross Detwiler understands the magnitude of his first-ever postseason start. When he climbs the mound at Nationals Park for Game 4 of the National League Division Series against the St. Louis Cardinals on Thursday, he could be staring down elimination or a series clincher. He will be facing a team that only two weeks ago bashed him around for seven runs, three earned, in only 2 1/3 innings.

As he spoke to reporters on the eve of his start, Detwiler, 26, was as comfortable and humorous as he often during the season. He joked that his last few starts of the season were an exercise of “what not do.” And, he has tried not to remember his loss to the Cardinals the final week of September, his last outing of the season. Instead, he vowed to be more aggressive.

“I’m just really going out there trying to throw strikes, trying to get ahead in the count,” he said. “You know, make the hitters hit my pitch instead of having to come after them 2‑1, 3‑1 like I was the whole time; limit the walks. I think I had five or six walks and I think that’s what really ended up hurting me.”

In watching the Nationals first games of the series, and the other playoff games on television, Detwiler has noticed that “you get hurt when the ball gets up in the zone and you try to stay out of that as much as you can.” Over his final six starts of the season, the left-hander went 3-3 with a 3.73 ERA and allowed opponents to hit. 250 off of him. He tailed off in his final two starts, struggling with command and walking 16 batters.

“A lot of these young pitchers, it generally takes – experience‑wise, generally takes a couple years,” Nationals Manager Davey Johnson said. “… Sometimes the problem that comes with good, young arms is you rely too much on your fastball. But I’ve seen him pitch some great ballgames. But you know, he’s got outstanding stuff, and he’s got good poise.”

Detwiler last started on Sept. 30, a layoff of 10 days. The closest equivalent was his 11-day break in between starts because of the July All-Star Game. In that game, the left-hander had one of his best starts of the season, allowing no runs and five hits over seven innings. For Thursday’s start, Detwiler would draw on that experience on how to stay sharp and effective with little work.

“It was the same there and I came back strong,” he said. “You know, I’ve been throwing and throwing bullpens. Just can’t wait to get out there tomorrow.”

Detwiler hopes that the confines of Nationals Park will be as helpful as they have been all season. In 90 1/3 innings at home this season, most as a starter, Detwiler is 8-2 with a 2.59 ERA. On the road, however, it balloons to a 4.39 ERA and a 2-6 record over 74 innings.

“I have no idea,” he deadpanned. “I’d be a whole lot better on the road if I knew that. But I think it’s just a routine thing. I’m able to get in the routine here. I have my places I go before starts at home, and obviously on the road, you’re in a different city, so you can’t do that. So hopefully that’s what it is and I’ll go about that tomorrow.”

Detwiler, like he does during the season before his starts, will wake up whenever he does, without an alarm. He will eat small meals, eating continuously, loading up on as many calories as he can without a big meal. And then, in the afternoon, he will take the ball with the Nationals’ playoff future in his hands.