Jeff Roberson/AP

Gio Gonzalez has never been in this situation before. In his five years in the major leagues, he has yet to reach the postseason until now. On Sunday afternoon, Nationals Manager Davey Johnson will hand him the ball to start Game 1 of the National League Division Series as the team’s top starter. The shivering he displayed on Saturday wasn’t because of nervousness about it, but because the chilly temperatures in St. Louis were unsettling for the Florida native.

“I’m trembling right now,” said Gonzalez, pulling his arms to his stomach and hoping the weather would stick to the forecast of highs in the 60s and sun for Sunday.

Not only will Gonzalez have to contend with a new situation on the mound, he’ll be doing so on prolonged rest. He last pitched on Sept. 27, with eight days of rest before Sunday’s start. His projected last start of the season on Tuesday was skipped out of fear of getting short rest if the Nationals were to play on Saturday. He was anxious to throw again, not wanting to give up Tuesday’s start but he was honored to be trusted as the Nationals’ No. 1 starter. He threw a bullpen session in between to stay sharp.

Gonzalez consulted with teammates such as Edwin Jackson, who has pitched in two World Series, including winning one last season with the Cardinals, about how to handle the playoffs. He, and others, told him to stick exactly with the routines that got him this far. Gonzalez usually gets a haircut before his starts, and on Saturday, he was already sporting a fresh, new haircut done by a friend from Miami whose nickname is Hugo Boss.

“To me, I try to stick with the same routine, have some fun,” he said. “ I know these guys, you’ve got to understand it, and what I’ve experienced in talking to some of the veteran guys that have World Series experience and playoff atmosphere is that, try not to change anything but understand that it will be very tough and pitches will be very tough.  You just have to mentally prepare yourself and pound the strike zone.”

Based solely on match-ups, it would sense to pair a right-handed starter against the right-handed heavy Cardinals lineup. But Gonzalez is deadly against left-handers and not far behind when facing right-handers. Left-handers are hitting .199 against him and righties hitting .231. For Johnson, and based on the year he has had, Gonzalez was the obvious candidate. (When told he would pitch, Gonzalez said his reaction was “back flips, cartwheels, excitement.”)

“When he’s locating his fastball, and he’s hitting the low side of the plate, he’s got a devastating curveball, I don’t care if they have all right‑handers out there,” Johnson said. “He’s tough …  Gio had one heck of a year.  I think he was lowest hits‑per‑inning and most clubs stack their clubs with right‑handers.  I admit, St.Louis has some awfully good right‑handers in the middle of the lineup, but you have to make good pitches.”

And there’s further evidence to suggest Gonzalez can handle their potent right-handed dominant lineup. His only career shutout came against the Cardinals on Aug. 31, in which he allowed only five hits. Right-handers in the lineup when 2 for 21 against him.

“It’s a different scenario [now],” Gonzalez said. “It was at home and now we are at their place.  Build a little more confidence when you’re at home, but now you know where you’re at.  These guys, they are alert and I’m going to have to be alert and going to have to change the game plan a little bit. Pretty sure they are not going to go out there with the same mentality.  Again, this is a team that knows how to bounce back and can make situations happen when they need to.”