HOUSTON -- There’s never a shortage of good storylines or good baseball when the Astros and Red Sox get together in the playoffs, which they’ll do in the American League Championship Series beginning Friday in Houston. This will be the third postseason meeting between the two clubs since 2017.

The Astros are clicking on all cylinders and playing some of their baseball of the season, taking out the White Sox in dominating fashion in four games in the AL Division Series. All that stands in their way of a third AL pennant in the last five years are the Red Sox.

Here are three keys to how Houston can come out on top:

A healthy Lance McCullers Jr.
McCullers’ Game 4 start against the White Sox on Tuesday in the ALDS was cut short after four innings because of tightness in his elbow. There was no update on his condition Wednesday, but whether he can take the ball figures to loom large in Houston’s chances in the series.

McCullers is the Astros' best starting pitcher and -- if healthy -- would be in line to start Game 3 of the ALCS at the earliest. He would then likely get the ball in Game 7, depending on how the series plays out. Lefty Framber Valdez is going to start Game 1 on Friday at Minute Maid Park.

Without McCullers, who missed the entire 2019 season after undergoing Tommy John surgery, the Astros’ rotation gets thin. Luis Garcia, who started Game 3 of the ALDS, and José Urquidy, who was scheduled to start Game 4 before it was pushed back a day because of rain, would both likely get multiple starts in a seven-game series.

If it’s Valdez, Garcia and Urquidy starting the first three games and McCullers is hurt, the Astros will have to find a starter for Game 4. That could mean activating Jake Odorizzi for the ALCS and having him start, or the Astros could go with a bullpen game. Zack Greinke and Cristian Javier, both starters-turned-relievers in this postseason, could factor heavily in a bullpen game.

“Pitchers have picked each other up in the bullpen,” pitching coach Brent Strom said. “I’m praying for the best-case scenario. If it’s not to be, then we have other capable starters. We’ll just have to see. Right now, I’m very optimistic [McCullers will] be fine.”

Keep mashing
The Astros, who led the Majors in runs scored (863) in the regular season, scored 31 runs in four games in the ALDS (7.75 runs per game) and scored at least six runs in each game. In fact, in seven games in October (including the final three games of the regular season), the Astros are slashing .311/.379/.538 with 13 homers and averaged 7.7 runs per game.

Unlike the regular season, the Astros have stuck with pretty much the same lineup, which means their top seven hitters are in the order together. How deep is that lineup? Yuli Gurriel, who won the AL batting title, batted seventh in the order for Game 3 of the ALDS. Jose Altuve, Alex Bregman and Carlos Correa have a terrific track record offensively in the playoffs and swung the bat well against the White Sox.

The Astros pounded Red Sox pitching in the regular season, scoring 42 runs in seven games (6.0 runs per game). In those seven games (5-2), they slashed .300/.386/.498 and hit nine home runs, including two in each of the three games at Fenway Park in June.

Kyle Tucker (12-for-25, six doubles), Michael Brantley (4-for-9), Gurriel (9-for-21, two homers), Yordan Alvarez (7-for-20), Correa (8-for-24) and Bregman (9-for-28) each were tough outs against Boston pitching this year.

Bullpen must step up
In a long series, especially if McCullers doesn’t pitch, Houston relievers may have to pick up even more innings in the ALCS.

The Astros’ bullpen had a 4.15 ERA in 17 1/3 innings in the ALDS and recorded one fewer out than the starting rotation (17 2/3 innings) did in the series. That’s because no Houston starter lasted five innings after McCullers’ gem in Game 1, in which he threw 6 2/3 innings against the White Sox.

In the Astros’ three wins in the series, their bullpen allowed one run and nine hits in in 12 innings. In a 12-6 loss in Game 3, it gave up seven runs and 11 hits in 5 1/3 innings. See a pattern? The bullpen was masterful in polishing off the White Sox in Game 4, with Yimi García, Kendall Graveman and Ryan Pressly each throwing a scoreless inning and Phil Maton throwing 1 2/3 scoreless.

García, Graveman and Maton were acquired at the Trade Deadline to bolster what had been a shaky ‘pen. Graveman has been the setup man since he was acquired, and García and Maton have had their ups and downs, though it’s clear they’re going to have to get big outs.

“[Yimi] García, in Game 3, with the home run by [Leury García], was a difficult blow for us, but he really fits well [against right-handed hitters] and he pitched exceptionally well [in Game 4],” Strom said. “A lot of credit goes to our GM and our analytics people to recognize Maton is a right-handed pitcher and has the uniqueness to get left-handed hitters out, and that plays well for us. Yimi is very solid against righties … and [Maton] is like having a really solid left-handed reliever, even though he’s from the right side.”

Maton will have to deliver in matchups against key Boston lefty bats including Kyle Schwarber, Alex Verdugo and Rafael Devers.