By Steve Ginsburg

WASHINGTON (Reuters) - The Washington Nationals insist their remarkable turn-around from bottom feeder to big wig will be wasted without a deep run into the playoffs.

Just three years after losing a big-league worst 103 games the success-hungry Nationals enter the postseason with the best record in baseball, buoyed by a top-shelf pitching staff.

Shortstop Ian Desmond said the team's 98-64 record will be forgotten when the Nationals visit either St. Louis or Atlanta in the National League Division Series on Sunday.

"At the end of the full year, we're all going to be sitting at home and remember what happened in the postseason not the regular season," he said. "Ninety-eight wins doesn't matter.

"The next step is what we've all been working for. That's pretty much what we're going to rest our hat on."

The Nationals have some big bats in the line-up but it is the starting pitching that has the nation's capital bracing for the possibility of its first World Series title since 1924.

Cy Young Award hopeful Gio Gonzalez (21-8, 2.89 earned run average), who arrived in an offseason trade with Oakland, highlights a staff where all five pitchers in the starting rotation posted double-digit wins.

Among those starters not in the line-up, however, will be flame thrower Stephen Strasburg (15-6, 3.16 ERA), who had reconstructive elbow surgery in 2010 and was shut down after pitching 159 innings this season as a precaution.

Nevertheless, with Gonzalez, Jordan Zimmermann, Edwin Jackson and Ross Detwiler, the Nationals still possess what is considered by many to be the best rotation in the majors.

Washington's offense suffered some early-season injuries and pitching that carried the load. When the bats returned, the Nationals were the league's most potent team.

"They were the anchor of this team," third baseman Ryan Zimmerman said of the starters. "We've said that from day one. Our offense was up and down because of a lot of injuries.

"In the second half of the season we got healthy and started scoring some runs. But for the first half they were solid. They gave us a chance to win every night."

With long-ball hitters Zimmerman, Adam LaRoche and Michael Morse complemented by Desmond and 19-year-old rookie Bryce Harper, the Nationals are primed to make the most of the second postseason appearance in the franchise's 44-year existence.

The Nationals had not had a winning season since arriving in Washington from Montreal in 2005 and Zimmerman said with the division series on the horizon he has had no time to reflect on the year.

"We really haven't had a chance to sit back and think about it," he said. "It's exciting. Hopefully we make it all the way and we can sit back and look at it.

"But for us to sit back and take it all in right now, it's impossible. We're still going."

(Editing by Gene Cherry)