To make the postseason -- or still be in the hunt at this late stage -- a team must have some significant strengths.

But no club is perfect, not even the ones that have reached triple-digit wins. And October baseball has a way of exposing flaws, big and small.

So before the postseason spotlight flips on, here is a look at each remaining World Series contender’s biggest weakness.

AMERICAN LEAGUE

Astros: Baserunning
All you can do with a 104-win team is nitpick, and in that spirit, Houston ranks 26th in the Majors in FanGraphs’ baserunning runs metric. (It’s not necessarily a blip, as the club ranked 28th last year, and 24th in 2017, and has not been above average since ‘15). The Astros don’t steal many bases, have a below-average success rate, and according to Baseball Reference, rank dead last in the Majors in the percentage of extra bases taken -- for example, advancing more than one base on a single. Snatching extra bases doesn’t matter as much when you are crushing home runs left and right, which Houston’s historically potent offense has done. But in a tight series against another powerhouse club, every little thing matters.

Athletics: Starting pitching
Once again, Oakland has managed to cobble together a solid rotation, adding Tanner Roark and Homer Bailey to fellow veterans Brett Anderson and Mike Fiers before the Trade Deadline. Even so, the A’s starter ERA is almost a run higher away from the spacious Oakland Coliseum, and is over 5.00 against other AL playoff contenders. It’s also a pitch-to-contact group that ranks near the bottom of the Majors in strikeout rate. Sean Manaea’s September return is reason for hope, but Frankie Montas is ineligible for the postseason, and it’s fair to wonder if Oakland’s starters will hold up as well against the postseason’s dangerous offenses, especially with the Crawford Boxes or Yankee Stadium’s short porch looming.

Rays: Hitting
Tampa Bay ranks sixth in the AL in park-adjusted wRC+ and ninth in runs per game, which suggests a solid but hardly spectacular offense. Ten Rays have posted an above-average wRC+ in at least 100 plate appearances with the team this season, but will that translate to postseason production against AL behemoths? Tampa Bay hit .220/.287/.390 against division-rival New York, .229/.272/.390 against Houston, and .222/.295/.361 against Minnesota this year. Also of concern in such matchups is that the Rays have the fifth-worst offensive production and fourth-highest whiff rate this year against the type of top velocity (95+ mph) they are sure to see in great quantity.

Twins: Starting pitching
Minnesota’s rotation has a 4.77 ERA in the second half, matching that of No. 1 starter José Berríos, who has allowed five or more runs five times since Aug. 1. But even if the Twins have a pair of solid options in Berrios and Jake Odorizzi, it’s an open question as to who else makes the club’s postseason rotation. Michael Pineda was lost to a suspension. Kyle Gibson is trying to overcome a battle with ulcerative colitis and might be used in relief. Martín Pérez has a 6.37 ERA in his past 20 starts. A bullpen game could be on the table at some point, but that may not solve all of the issues here.

Yankees: Health
They have shown an amazing ability to thrive despite a staggering amount of injuries. Still, it’s worth wondering how the Yankees’ various maladies might affect their October chances. New York is lacking a shutdown reliever (Dellin Betances) and two solid outfielders (Aaron Hicks, Mike Tauchman), has two sluggers (Edwin Encarnacion and Gary Sánchez) still trying to make it back in time for the playoffs, and a starter (Luis Severino) plus another slugger (Giancarlo Stanton) who only just returned from a long IL stints. The hits keep on coming, too, with third baseman Gio Urshela sustaining a bruised hand Tuesday. (Starter Domingo Germán also will be on administrative leave through the postseason). Could a missing or rusty player finally wind up costing the Yanks?

NATIONAL LEAGUE

Braves: Relief pitching
Assuming Ronald Acuña Jr. and Freddie Freeman are healthy, the biggest question mark is a bullpen that ranks in the middle of the pack in most significant categories this season and has an ERA over 5.00 since the All-Star break. Atlanta did trade for reinforcements during the season, acquiring the likes of Mark Melancon, Shane Greene, Chris Martin, and Anthony Swarzak. Darren O’Day also has been solid in a September return from a season-long IL stint, but this still may not be the type of shutdown, bat-missing unit a team would love to have for October.

Brewers: Starting pitching
If losing your potential back-to-back MVP winner to a freak, season-ending injury counts as a weakness, then that’s it for Milwaukee, which is enjoying a red-hot stretch run even without Christian Yelich. Otherwise, it’s the lack of elite starters in a rotation that has the second-highest ERA (4.47) of any team on this list. The July trade for Jordan Lyles and recent return of Brandon Woodruff from injury have been positive developments. Yet manager Craig Counsell still figures to get creative with his pitching staff -- as he did last October -- in an effort to mitigate this weakness and take advantage of the club’s depth of quality arms.

Cardinals: Hitting
There are three teams this season that do not have a single player with at least a 120 OPS+ (20% above league average) in at least 100 plate appearances. Two are the Marlins and Tigers, both of whom already have surpassed 100 losses. The third is the Cardinals, who rank near the bottom of the NL in runs per game. The club is led by the 117 OPS+ that rookie Tommy Edman has posted since his midseason callup. Paul Goldschmidt has not brought quite the MVP-level bat St. Louis thought it was getting, Matt Carpenter’s numbers have plummeted, and Paul DeJong and Marcell Ozuna have both slumped in September.

Dodgers: Relief pitching
There are plenty of question marks here. Is Joe Kelly, who has pitched much better in the second half, fully healthy? Which pieces of the team’s enviable rotation depth will be used in relief? Can rookies Tony Gonsolin and Dustin May be counted on in big spots? But the biggest question of all concerns closer Kenley Jansen. Can he rediscover his All-Star form in time? To this point, Jansen has by far the highest ERA of his career (3.77) and has blown eight save chances -- coming off his two blown saves in last year’s World Series.

Nationals: Relief pitching
This one isn’t complicated. This season, Washington has the highest relief ERA (5.77) of any team not named the Orioles. It’s also the highest of any team in MLB history that’s qualified for the postseason, passing the 1997 Mariners (5.47). Trade Deadline acquisition Daniel Hudson has helped, but he is the only pitcher to post an ERA under 3.97 in more than one relief appearance for the Nats this season. A lot will depend on if Sean Doolittle -- who just earned his first save since mid-August -- is ready for his usual high-leverage/closing role following his return from a knee injury.