It happens every year: A team already eliminated from the postseason meets a team fighting hard for a playoff berth late in the season — and the underdog wins!
Unexpected spoilers can be one of the most fun parts of September baseball (unless your favorite club finds its postseason hopes affected, of course). And with the postseason picture beginning to take shape, several frisky clubs on the outside could make things difficult for MLB’s top contenders.
Here are five teams that could serve as spoilers this September.
Angels (66-74)
Need an example of how the Angels can cause problems for a contending club? Just ask the Dodgers. The Halos swept the 2025 Freeway Series with a 6-0 record, flummoxing the defending World Series champions in May in Chavez Ravine and again in August in Anaheim. The Angels also own series wins over the Phillies and a who’s who of American League contenders: the Blue Jays, Guardians, Mariners, Red Sox (twice, including a three-game sweep), Royals, and Yankees.
The Angels win games with power: They’ve slugged the fourth-most home runs in MLB, behind only the Yankees, Dodgers and Mariners. Outfielders Jo Adell and Taylor Ward have each reached the 30-homer plateau, while Zach Neto, Mike Trout and Logan O’Hoppe are also major power threats. With a four-game road set in Seattle coming up from Sept. 11-14 and six home games against the Royals and Astros to end the regular season, the Angels have an opportunity to stir up the AL postseason race.
Athletics (64-77)
On the strength of another standout second half, the A’s have made our list of potential spoiler clubs for the second straight year. They’re 23-20 since the All-Star break, and they’ve beaten some of MLB’s top teams along the way. The A’s swept the Astros in a four-game series in Houston, took two of three from the Mariners after that and swept the Tigers last week at Sutter Health Park.
What’s behind their latest surge? The A’s boast a dangerous lineup featuring rookie standouts Nick Kurtz and Jacob Wilson, catcher Shea Langeliers — whose 17 home runs since the break are tied for the most in the AL — and sluggers Brent Rooker and Tyler Soderstrom. Rookie starter Luis Morales has been impressive since his Aug. 1 debut, too. With six games left against the Red Sox and three apiece against the Reds and Astros, the A’s could easily spoil someone’s September.
Braves (63-77)
The 2025 season hasn’t gone at all how the Braves envisioned, but that doesn’t mean they can’t still be a threat. While Atlanta’s pitching staff has taken some major hits — all five members of the Opening Day starting rotation have spent time on the injured list — the bats are still potent. Ronald Acuña Jr., Matt Olson and Marcell Ozuna still make up the heart of the order, and Jurickson Profar and Michael Harris II have been hot.
Despite being 14 games under .500 on the year, the Braves have played a bit better since the All-Star break, going 21-24 with quite a few wins over contending clubs. In the span of three weeks, they took two of three from the Reds and Mets, then swept the Guardians — all on the road. With nine straight games against contenders (the Mariners, Cubs and Astros) beginning Friday and a three-game road set against the Tigers from Sept. 19-21, the Braves have plenty of chances to cause some disruptions in both leagues’ postseason races.
D-backs (70-71)
The D-backs are MLB’s unofficial “chaos team,” and not much says chaos like high-stakes September baseball. So it only seems fitting that Arizona’s late-season schedule is chock full of contenders. The D-backs host the Red Sox from Friday to Sunday and close 2025 with nine games against three elite NL clubs — the Phillies, Dodgers and Padres. The D-backs have proven they can handle contending teams, coming off four series wins and a four-game split in a lengthy stretch against five postseason hopefuls (the Guardians, Reds, Brewers, Dodgers and Rangers).
A lineup led by Corbin Carroll and Ketel Marte makes Arizona perpetually dangerous, even after trading Eugenio Suárez and Josh Naylor to the Mariners in separate Trade Deadline deals. Shortstop Geraldo Perdomo, one of the league’s most well-rounded players, is in the midst of a breakout season. The D-backs pitching staff has struggled, but this team still has most of the pieces from its 2023 World Series run. Contenders beware.
With their plethora of big bats and a resurgent Trevor Rogers dominating in the rotation, Baltimore has what it takes to surprise an opponent or two down the stretch. The O’s will have plenty of chances, too: After back-to-back series against the Padres and Dodgers, they have a road series in Toronto (Sept. 12-14) and seven games against the Yankees still to come. If the Orioles can muck things up for one of their division opponents, it could be a bit of a silver lining to a tough year.
