The National League Central has played out as anticipated this season, but with a few unexpected developments.

The division was expected to be a three-horse race come September, and the Brewers, Cardinals and Cubs have delivered in that regard. What the preseason prognosticators probably did not necessarily envision was St. Louis in the driver's seat, with Chicago and Milwaukee in the rear-view mirror for the final lap.

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Over the next few weeks, those three teams will try to punch their ticket to October, but each club still has some important questions to answer down the stretch. The same goes for the Reds and Pirates, who are beginning to evaluate their rosters with the future in mind.

In this week's NL Central notebook, MLB.com is looking at one looming question that each team must answer over the final three weeks of the regular season.

Brewers: Can they bullpen their way through another September?

Jordan Lyles pitched into the seventh inning of a big win over the Astros on Tuesday, but he’s the outlier in a rotation that is short of pitchers who work long in games. Sometimes that's by choice. The Brewers tend to use the "initial out-getter" twice through an opponents' lineup and then match up with the relief corps the rest of the way. It's doable with expanded rosters in September, as evidenced by the Brewers beautifully in 2018.

But there are some additional challenges this year: fewer off-days on the schedule, and only one of the three-headed bullpen monster of Josh Hader, Jeremy Jeffress and Corey Knebel. Jeffress was released this week, and Knebel is rehabbing from Tommy John surgery. The Brewers do have one important arm on the way: All-Star starter Brandon Woodruff is working back from an oblique injury and should be ready to pitch in short bursts by the middle of the month.

Cardinals: How will they handle the schedule?

Except for the next week against the Pirates and Rockies, the Cardinals face contending teams the rest of the month. The Brewers, Nationals, Cubs, D-backs and Cubs to end the regular season isn't a terribly easy path to clinching a postseason berth, especially with how tight the division and Wild Card races are.

The Cardinals don't need to be reminded of last season, when they rose to relevance in August with 22 wins only to run out of gas in September by going 7-10 to end the season, including losing five of their last six games to the Brewers and Cubs. To shove their way into the postseason this year, the first-place Cardinals will need to finish strong against teams all motivated to beat them.

Cubs: Can Ben Zobrist seize the job at second base?

The veteran Zobrist is in a position to build back up to a regular role at second base, but the Cubs are faced with the reality that he missed nearly four months while on the restricted list. While he was away, Chicago cycled through Addison Russell, David Bote, Ian Happ, Robel Garcia, Daniel Descalso and Tony Kemp at second. Entering their four-game series against the Brewers, which begins on Thursday at Miller Park, the Cubs have gotten a .219 batting average and .684 OPS from the second-base position this season.

Over the final few weeks, Chicago needs to monitor Zobrist's swing and stamina, using built-in off-days to keep the 38-year-old fresh. His performance will help the Cubs determine how to manage that spot in the infield by the time a potential postseason run arrives.

Pirates: Who deserves a spot in next year’s rotation?

Pitching was supposed to be Pittsburgh’s strength this season, as the club planned to build around a rotation fronted by 2018 second-half standouts Jameson Taillon and Trevor Williams with a resurgent Chris Archer. But the Bucs' rotation enters play on Thursday with a 5.22 ERA that ranked 25th in the Majors. On top of that, Taillon (Tommy John surgery) won’t return until 2021.

What's left is a starting staff full of question marks and underperforming pitchers. Will Williams, Archer, Steven Brault, Joe Musgrove and Mitch Keller show any signs that they can carry the load in 2020? Or will their struggles this season convince Pirates management to either rebuild around their young position players or add more proven starters in an effort to reload for next year?

Reds: Is Aristides Aquino the real deal as the Reds plan for 2020?

It has been the stuff straight out of a movie script. The 25-year-old Aquino -- non-tendered and re-signed by the Reds over the offseason -- slugged his way to the Majors by August and hasn't looked back. Seven homers in his first nine games. Eleven in his first 16 games. Rookie power records falling. A National League Player of the Month Award came his way. So did the Rookie of the Month honor.

Now, the Reds will monitor how Aquino performs within baseball's cat-and-mouse game. Already, pitchers are starting to shift their approach. For example, 11.1 percent of pitches thrown to Aquino between Aug. 1-15 were sliders. That rate has spiked to 24.6 percent since that stretch. Over the final month, it will be important to see how Aquino adjusts as the book on him thickens, and whether this breakout showing portends elite-level production in 2020.