Ric Flair said it best: “To be the man, you gotta beat the man.”

So it’s only fitting the Boston Red Sox, winners of 108 games during the Major League Baseball regular season, must take down the defending World Series champion Houston Astros in the American League Championship Series to punch their ticket to the 2018 Fall Classic.

Now, there’s a lot to like about this year’s ALCS. Not only are the Red Sox and Astros both stacked. But there also are several connections between the teams, including Alex Cora managing Boston after serving as Houston’s bench coach last season and J.D. Martinez playing against the franchise that released him in 2014 long before he evolved into an MVP candidate.

That said, it’s often the players flying under the radar who make the biggest impact. Just look at the Red Sox’s American League Division Series victory over the New York Yankees, during which Boston received major contributions from Brock Holt, Steve Pearce and Nathan Eovaldi, to name a few.

So, who might unsuspectingly change the course of MLB history in the Red Sox vs. Astros ALCS? There are several candidates. Let’s examine three potential X factors for each team.

Mitch Moreland, 1B
It was unclear as of Friday afternoon whether Moreland even will crack Boston’s ALCS roster, as the first baseman is dealing with a hamstring injury that limited him during the ALDS. But don’t sleep on Moreland if he suits up for the Red Sox. Although he had a forgettable second half and Pearce has performed admirably in his stead, Moreland boasts a relatively successful track record against Game 1 starter Justin Verlander: .313 average (10-for-32) with six doubles, six RBIs and an .871 OPS. He also has plenty of big-game experience, having played in two World Series with the Texas Rangers, and he went 5-for-13 with two doubles and four runs scored in last year’s ALDS against Houston.

Jackie Bradley Jr., CF
Minute Maid Park in Houston features some weird dimensions, including a left field that jets out to the right of the Crawford Boxes and a spacious right-center field. Thus, Bradley’s range — and the range of the Red Sox’s outfield, collectively — could be a difference-maker in slowing the Astros’ offense, provided Boston’s hurlers can keep the ball in the yard.

Ryan Brasier, RHP
Give credit to Brasier for bouncing back from a miserable playoff debut in Game 1 of the ALDS and actually looking like a viable late-inning option when the dust settled. Brasier tossed a scoreless seventh inning in Game 4 against the Yankees, paving the way for Chris Sale in the eighth and Craig Kimbrel’s roller-coaster ninth. If Brasier can perform at a high level, like he did for much of the season, then the Red Sox’s bullpen looks far more stable. Either way, it’s apparent Red Sox manager Alex Cora trusts him.

Martin Maldonado, C
The Red Sox ranked third in the majors in steals during the regular season (125) and aren’t afraid to apply pressure on the bases whenever possible. Assuming they stay true to their identity in this series, Maldonado’s performance behind the plate will be of the utmost performance, and there’s no reason to believe the 2017 Gold Glove Award winner won’t be up to the task. Maldonado threw out 49 percent of would-be base stealers this season, including five of eight after a midseason trade to the Astros, who addressed a significant need in acquiring the defensively-gifted backstop.

Ryan Pressly, RHP
Speaking of midseason acquisitions, the Astros’ trade for Pressly has been huge. He’s been dominant since joining Houston, posting a 0.77 ERA, a 0.60 WHIP and 12.3 strikeouts per nine innings in 26 regular-season appearances. FanGraphs’ Jeff Sullivan even wrote an in-depth piece Friday about just how unhittable he’s been. Yet Pressly continues to get overshadowed by his peers in Houston’s bullpen. That could change in the ALCS, when he’ll undoubtedly pitch meaningful innings on the big stage.

Lance McCullers Jr., RHP
McCullers was sent to the bullpen thanks to a midseason injury and the overall depth of Houston’s starting rotation, but that doesn’t mean he won’t have a significant role against the Red Sox. The hard-throwing right-hander was vital to the Astros’ 2017 World Series triumph, even tossing four shutout innings against the Yankees in Game 7 of last year’s ALCS, and it’s possible, if not likely, Houston manager A.J. Hinch will rely on McCullers for key outs as a multiple-inning option versus Boston.

Thumbnail photo via Bob DeChiara/USA TODAY Sports Images