ATLANTA -- One trait the Cubs have leaned on all season has been resiliency. When the team fell well below the break-even mark in June, it climbed steadily back to a winning ledger. When the Trade Deadline loomed and there was a real threat of subtraction with the future in mind, the team piled up wins in a hurry and forced the front office to change course.

The Cubs badly need to rediscover that characteristic over the regular season’s final three days.

“We’ve got no choice,” Cubs shortstop Dansby Swanson said.

On Thursday night, Chicago was dealt a 5-3 loss at the hands of the 103-win Braves at Truist Park. The victory for Atlanta helped the club secure home-field advantage throughout the postseason, including the World Series. For the Cubs, the sweep dropped them out of the current playoff field.

• Games remaining (3): at MIL (3)
• Standings update: The Cubs (82-77) sit just outside the third and final National League Wild Card spot. The Marlins (82-76) are a half-game ahead of Chicago and own the tiebreaker between the two clubs. The Cubs are also two games behind Arizona (84-75) for the second NL Wild Card, and Arizona owns the tiebreaker over the Cubs.

In Atlanta, the Cubs saw the bar they have to reach.

“To get where you want to go, that's where you have to get. There's no point in not realizing that,” Cubs president of baseball operations Jed Hoyer said of the Braves. “Right now, they are the best team. I don't think anyone would argue with that. And to beat them over the long haul, you've got to be better than that. And that's a good standard to have.”

After two years of rebuilding, the Cubs have a team balanced with youth and October-tested veterans. Together, they have pushed Chicago to the edge of the postseason race, which is a testament in itself to how far the club has come from early in the summer months.

The fade down the stretch has been a reminder that this is still very much a work in progress for the Cubs.

“We talked about, like when we start Spring Training, being a better version of ourselves now than then,” Cubs manager David Ross said. “And we are. We’re a better team than we were to start this season, and I think everybody can hold their hat on that.

“But there’s still a long way to go to be a championship, World Series-caliber baseball team. And that’s what we’re shooting for.”

“They’re a good team. They’re not far off,” Braves third baseman Austin Riley said. “They’ve got a lot of good pitching and a lot of good players.”

The North Siders still have a glimmer of hope when it comes to punching their ticket to the October party, but Atlanta has given them a reality check. The Braves feature a potent lineup that came into Thursday with the highest slugging percentage (.501) in AL/NL history, and they are the third team in AL/NL history to launch 300-plus homers.

On Wednesday night, the Cubs watched Ronald Acuña Jr. hoist second base over his head in celebration of becoming the only player to reach 40-plus homers and 70-plus steals. Then, on Thursday, Matt Olson crushed a Marcus Stroman pitch for his 54th homer and club-record 136th RBI.

“That lineup is incredible,” said Stroman, who lasted only two innings in his second start back in the rotation after a stint on the injured list. “One through nine, they're solid, man. You have to be locked in from pitch one. They don't give you any breaks.”

The Cubs -- a strong defensive team all season, ranking fourth in the NL with 20 Outs Above Average coming into the night -- made a series of miscues throughout the sweep.

Right fielder Seiya Suzuki had a costly missed catch on Tuesday. Second baseman Nico Hoerner made an errant flip to Swanson on Wednesday. In the finale, Gold Glove left fielder Ian Happ fumbled a sliding catch attempt, opening the door for two runs. Those were only a few of the blunders.

“We've got to play clean baseball,” Ross said. “We're better when we do that, right? The pitching and defense, that's been our signature when we're having success.”

And the mark of an upper-echelon team like Atlanta is jumping on those chances.