Washington Nationals players expressed a mixture of pride and regret after their loss to the Giants on Tuesday, with some already looking forward to spring training. (Whitney Leaming/The Washington Post)

The visitor’s clubhouse at AT&T Park was near silent. The only sounds were players talking to reporters, packing up their belongings and hugging each other goodbye. The man who built the team, General Manager Mike Rizzo, made his way around the room, talking and shaking hands with each player.

For the past eight months, Washington Nationals coaches, officials and players have spent nearly every day together. The next time they assemble — in four months in Viera, Fla., for spring training — the team won’t be the same. The core will return but a few faces, such as Adam LaRoche and Rafael Soriano, are likely to depart.

“It’ll take a few days, maybe even a few weeks, to be able to look back on the season because it ended so quickly,” reliever Jerry Blevins said late Tuesday night after the season-ending loss to the San Francisco Giants.

But soon after the shock wears off, the Nationals’ self-evaluation will begin in earnest, starting with the composition of the roster.

Core pieces — Ian Desmond, Jordan Zimmermann, Denard Span, Doug Fisterand Tyler Clippard — are under team control for only one more season, after which they are eligible for free agency. This group has helped the Nationals win 280 games over the past three seasons, the most in baseball, but the opportunities to win a World Series are dwindling . There is an urgency inside the organization to win with this group now.

“We’ve got a lot of talent and a lot of good ballplayers that are under contract and coming back for a while,” said Desmond, who is owed $11 million in 2015 but is then eligible for free agency after the season. “The window isn’t closed, but it is closing. It’s important for us to move past this and go to spring training ready to go.”

The most notable changes to the Nationals’ roster likely will be in the bullpen and infield. LaRoche has been an important part of the lineup over the past four seasons, but he may be pushed out. LaRoche, 34, has a $15 million mutual option for 2015. Although he loves Washington and his teammates and Rizzo has a lot of respect for him, the Nationals will need to find a spot in the lineup for Ryan Zimmerman.

“I have no idea what direction I’ll go from here,” said LaRoche, who is owed a $2 million buyout if his option is not picked up. “But I know I’ll go sit in the tree stand [to hunt] and think about it.”

The Nationals were a better team with Anthony Rendon’s glove at third base. Zimmerman’s worn right shoulder is better suited for first base or even left field, a position he learned this season and enjoyed. But if the Nationals pick up the $9 million club option on Span, a relative bargain for a player who hit .302 from the leadoff spot and played excellent defense, then the outfield of Bryce Harper, Span and Jayson Werth will be set again.

So if Zimmerman plays first base, the Nationals’ biggest question mark will be second base. Danny Espinosa, a stellar defender, struggled again offensively, hitting .219 with 122 strikeouts, and returned to his backup role when the Nationals traded for Asdrubal Cabrera at the July 31 deadline. The Nationals could re-sign Cabrera — who solidified the infield during the team’s hottest stretch, though he hit .229 — or acquire a second baseman.

Cabrera, 28, loves playing shortstop and would like to return to the position he has played most of his life, but he switched to second base for the Nationals. His range at his age may be best suited for second.

“It depends,” he said. “A team like this team, a winning team, I would love to play second and love to stay here. I just want to win. I’ve got eight seasons already. I want to be in the World Series one day.”

The Nationals’ depth can fill the likely hole at the back of the bullpen. The team holds a $14 million option for Soriano for next season. He saved 75 games and posted a 3.15 ERA in that span, but given how he struggled in the second half of this season and how well former closer Drew Storen pitched in the ninth in his stead, the Nationals have an obvious replacement.

“Once the playoffs finish, we’ll see what’ll happen,” Soriano said.

Although their window to win has narrowed, the Nationals will be in good position to contend again for an NL East title because of the foundation of their team. Their starting rotation, which led the majors in ERA, will return intact. Clippard, Storen, Blevins, Craig Stammen, Aaron Barrett and Matt Thornton are under team control next season, and the Nationals could lean on its deep pitching depth to fill spots. Ross Detwiler, converted from starter to reliever before the season and then left off the playoff roster, could be a potential trade candidate.

The infield will be led by Desmond, Rendon and Zimmerman. Harper’s strong October showed how important he is to the Nationals’ future. The bench could feature Kevin Frandsen and Nate McLouth again next season, with some upgrades after the likely departures of Nate Schierholtz and Scott Hairston.

“Our core group guys is pretty much intact,” Zimmerman said. “There’s not too much change. There’s probably some change. Haven’t really thought about it yet. But we’ve got a good thing going.”