The No. 6 seed Houston Astros and No. 2 seed Oakland Athletics will soon meet up in the best-of-five American League Division Series to determine who advances to the ALCS to face either the Rays or the Yankees. Against that high stakes backdrop are the recent tensions between these two AL West rivals. While this isn't exactly a timeless baseball feud -- the Astros have been in the American League since just 2013 -- the two sides have cultivated serious hostilities in that brief span of time. 

"As a vindictive kind of thing, we want to take out the Astros," A's closer/warrior-poet Liam Hendriks said recently. "But I don't care who we play. As long as we beat them."

More from Hendriks: 

Duly noted by those who enjoy simmering tensions, which includes you and me and all of us. Relatedly, the A's during the regular season won seven of 10 head-to-head match-ups against Houston, and in those games Oakland out-scored them by a margin of 38-25. In the overall series, things are much tighter as the A's lead by the slimmest possible margin of 75 wins to 74. So, yes, Game 1 of the ALDS, which will mark the first time these two teams have met in the postseason, will occasion their 150th meeting. Intrigue levels increasing!

So as we get set for what figures to be a highly compelling series, let's get up to speed on why the A's and Astros probably don't like each other all that much. Let us commence this walking tour ... 

Fiers blows the whistle

Aside from the usual baseline of intradivisional contempt that flows from playing each other 19 times per season in normal years, the story mostly begins with Mike Fiers, Oakland right-hander, as disaffected whistleblower. Before the ongoing COVID-19 pandemic came along, the Astros' sign-stealing scandal was scandalizing baseball, and Fiers played an essential role in bringing that scandal to light.

On Nov. 19 of last year, Ken Rosenthal and Evan Drellich of The Athletic dropped a bombshell report that alleged the Astros electronically stole signs throughout the 2017 season. The veteran pitcher Fiers, with the A's at that point but previously a member of the Astros, served as the on-the-record source for the report. According to Fiers, the Astros had a center-field camera fixed on the catcher, and someone decoded the signs in real time on a monitor in the hallway between the dugout and clubhouse. Then someone banged a garbage can to relay incoming pitches to the hitter. 

Fiers' claims prompted an MLB investigation, which subsequently determined that the Astros used the scheme during the 2017 regular season and postseason, when they won the World Series, and partway into the 2018 season. As part of the fallout, then Houston manager A.J. Hinch and general manager Jeff Luhnow were forced out, draft picks were forfeited, fines were levied, the Astros' reputation was tarnished beyond repair, and the legitimacy of the only championship in franchise history was called into doubt.

Needless to say, Fiers in Houston and environs and perhaps within the Astros' clubhouse is likely regarded as something of a snitch. Indeed in February of this year, Fiers told Susan Slusser of the San Francisco Chronicle that he'd received death threats in response to his disclosures. Notably, none of his 11 regular seasons starts came against the Astros, so he hasn't faced his former team since blowing their cover. "It looked funny, but if you go back and look at when we started the season and we didn't doctor our rotation at all along the way, he just missed them every time," A's manager Bob Melvin told reporters on Saturday. "I'm very comfortable saying that because I know we never did anything to our rotation to make him miss the Astros and yes he is definitely a potential (option) for this series."

Given that there are no off days during the 2020 Division Series, Fiers may indeed get a start against Houston should the series goes long enough. It goes without saying such a turn of events would ramp up the intrigue to never before seen levels.

The Lucroy scoop

It wasn't just Fiers who suspected the Astros were up to something. Even on the A's, Catcher Jonathan Lucroy, who was Oakland's primary behind the plate in 2018, said in February of this year that the A's first called Houston's sign-stealing to the league's attention but that it wasn't until after Fiers went public that an investigation was undertaken. Lucroy no longer has any connection to the A's, but he revealed that it was the A's who first attempted to "tattle" on the Astros. If MLB had acted on that information, then Fiers would not have felt compelled to tell the story to the media. In either case, it's the A's who shined light on the Astros' malfeasance. 

L'Affaire Laureano-Cintron

Let us of course not forget the near fisticuffs between A's fly-catcher (and former Astros draftee) Ramon Laureano and Astros hitting coach Alex Cintron back on Aug. 9. Laureano had just been plunked for the second time in the game and was in an understandable state of agitation. Upon reaching first base, Laureano exchanged expletives with Cintron. Cintron then took it to another level entirely by saying "in Spanish something you don't say about my mother," according to Laureano. 

Then this happened: 

Laureano, as you witnessed, was willing to punch his way through the entire Houston roster to get to Cintron, who was content to continue taunting from behind a heavily garrisoned front line. While Laureano didn't get to land the literal haymaker of his dreams, he did catch Cintron square on the button in the figurative sense. Of Cintron, Laureano later said

"I regret charging him because he's a loser."

All eyes on Mr. Laureano once this series begins.

And, heck, the Dodger Stadium backdrop

While this facet doesn't have anything to do with the A's, let's note the setting for this series -- Dodger Stadium. MLB is operating a pair of postseason bubbles in Southern California and Texas for the LDS and LCS rounds, and the A's and Astros will be playing all of their ALDS games on the field where Houston clinched the 2017 World Series. That, to repeat, is the season in which the Astros were heavily invested in their sign-stealing scheme. 

Who knows, maybe the Astros' bus route will take them past the mural devoted to the Pouty Face That Launched a Thousand Ships

Maybe the glimpse of Joe Kelly's mug will put the Astros in a fittingly sour mood for the ALDS. Let the righteous anger flow from all sides.