CHICAGO -- Chicago Cubs manager Joe Maddon often says a team has to go out and take what it desires because nothing is going to be given in baseball -- not over 162 games.

The Milwaukee Brewers are heeding Maddon's advice, as two September series wins over their rivals have brought them within a game of the National League Central lead.

The Cubs are hearing footsteps.

"They're definitely coming for us," said Kyle Hendricks, Wednesday's losing pitcher. "We can feel it."

The Brewers have a combination of left-handed thump at the plate and a generational left-hander on the mound. Reliever Josh Hader faced 10 Cubs hitters in the two Milwaukee victories. He struck out nine and gave up a base hit. In fact, according to Elias, going back to his past three appearances, Hader is the fourth pitcher in the past three seasons to strike out at least nine in a row. He was electric, sucking the life out of the Cubs and the Wrigley Field faithful.

"He's hard because the way he throws," Javier Baez said, stating the obvious. "It's tough to catch up."

It doesn't help that the Cubs are about as fatigued as a team can be right now. After Wednesday night's 5-1 loss, they were packing their bags for an overnight flight to Washington, where -- weather permitting -- they'll play a makeup game with the Nationals before coming right back to Chicago for a weekend series against the Cincinnati Reds. Then comes a quick trip two time zones west for three games against Arizona before another overnight flight home and finally -- after 30 straight days at the ballpark -- a day off.

The stretch might be one reason the Cubs aren't scoring. Even all-world hitter Daniel Murphy is in a slump. He was 0-for-11 in the series against Milwaukee.

"I got my teeth kicked in," he said.

The same can be said for the entire offense, as well as the Chicago bullpen. The hold the Cubs have had on the division feels like it's slipping away. And the Brewers are ready to pounce.

Milwaukee's Curtis Granderson celebrates after his ninth-inning home run extended the Brewers' lead. AP Photo/Matt Marton

"The games have been tight, especially the games here at Wrigley," Milwaukee manager Craig Counsell said earlier Wednesday. "For me, it's two good teams battling each other. It's what you would expect."

Right now the Brewers have an edge, particularly in the form of Hader. A best-of-five playoff series with two off-days built in would give Counsell the chance to max out the lefty. If the Cubs and Brewers end up meeting in October, there could be a changing of the guard, just as there was in 2015, when the Cubs took what the St. Louis Cardinals had owned for so long: division supremacy.

"That's a really good team over there," Hendricks said. "They've been playing us close between last year and this one. They're our biggest rival for sure at this time."

There it is: the "R" word. It wasn't long ago that Cubs pitcher Cole Hamels declared there was no rivalry because so many Cubs fans were invading Miller Park, giving the visitors a distinct home stadium feel. But a tight race to the finish might change how everyone looks at the Brewers -- if that hasn't happened already.

"That was a big series," Hendricks said. "We played OK, but they played better than us."

But before anyone counts out the Cubs, consider the culture Theo Epstein and Maddon have created. They've mastered taking it one day and one game at a time. There's no better evidence of that than the 2016 World Series, in which the Cubs trailed three games to one before rallying to victory.

Or how about their hangover year in 2017? Maddon & Co. navigated the expected physical and mental letdown associated with winning the franchise's first World Series in 108 years, eventually pushing the right buttons for a third straight trip to the NL Championship Series. Can they rally again in the midst of an arduous schedule?

"We're in the same place [mentally] we've always been," Hendricks said. "Maybe a little tired, to be honest, but we're fine. We know where we are. We know where we want to get to."

So do the Brewers. They're no longer the little upstart team that faded last September. They are as dangerous as anyone in the NL, including the team that is just a single game ahead of them in the standings. Maddon hears those footsteps as well and is asking his team for more, especially on offense. The Cubs tallied just six runs in this series.

"We have to get better," Maddon said. "There is no other way of looking at it. We need to swarm again, like we had been doing earlier this year. There might be some fatigue in there. They're not admitting to it, but it's just a fact."