HOUSTON The signs were there all season, really. The harder the 2017 Yankees were punched in the gut, in particular those forgettable nights when Aroldis Chapman gave away games to the Red Sox, the more ferociously they fought back the next day.

At some point you couldnt help but think there was something special about this group, and indeed as they peaked in September scouts were telling me to beware these Yankees.

But Ill admit, I didnt think they could beat the Indians, and, as it turned out, maybe Corey Kluber wasnt completely healthy, as he and Terry Francona both hinted at after Game 5.

Nevertheless, coming from down 0-2 against a superb Cleveland team, even amidst all the Joe Girardi-hysteria, has to rank as one of the great comebacks in postseason history.

And a lot of it was born from that same mental toughness we saw all season, whether it was Brett Gardner stunning the Cubs at Wrigley Field in May or Matt Holliday taking Craig Kimbrel over the Green Monster in July.

All of which is a way of saying: Im buying in on these Yankees as they move on to take on the Astros in the ALCS.

This, after Ive been on the Stros from the start, picking them to win the World Series in our Daily News predictions in March.

And in some ways they could be tougher to beat than the Indians, with the most explosive offense in baseball, but it just feels like the Yankees are playing at such a high level right now, riding a wave of confidence and relishing their status as underdogs, that theyll find a way.

I do wonder if that comeback against the Tribe took an emotional toll, to the point where the quick turnaround for the ALCS could be a disadvantage. Ill always remember, as crazy as it sounds, the 86 Mets being flat for the first two games of the World Series, admitting later they were drained by the epic NLCS against the Astros.

Girardi argued otherwise here on Wednesday, saying he believes that winning three straight elimination games would only lift his team coming into this series.

I think were on an emotional high, he said. Our guys are in a good state mentally.

If thats the case it should be a classic series, featuring the two highest-scoring teams in the majors this season: The Astros racked up 896 runs, 38 more than the Yankees, but the Bombers out-homered them 241-238.

The Astros beat up on Red Sox pitching in their four-game ALDS as well, averaging six runs per game while hitting .333 and posting a rather staggering .974 OPS.

Furthermore, Yankee starters didnt fare well against the Astros this season, but they hadnt pitched well against the Indians either during the regular season. Everything changes in the postseason, and Masahiro Tanaka, Luis Severino, and CC Sabathia all offered reason in the ALDS to believe theyll at least hold their own against the Astros.

Meanwhile, Dallas Keuchel has been a Yankee-killer, especially in that wild-card game in 2015 when he threw six shutout innings, and he pitched to a 2.87 ERA in September to quiet concerns about him after two disabled-list stints for a neck injury.

Still, scouts who saw him even late in the year say he didnt have that otherworldly command of his two-seam fastball or quite as much late movement on his change-up as he does when hes at his best, so that will bear watching.

Getting Justin Verlander on Aug. 31 was crucial for the Astros hopes of winning it all, but quite the opposite of Keuchel, hes a guy the Yankees have had a lot of success against over the years.

Meanwhile, Girardi has lined up his starters so that Masahiro Tanaka and Luis Severino will pitch Games 1 and 2 against Keuchel and Verlander, respectively, with CC Sabathia and Sonny Gray in Games 3 and 4.

I thought Girardi might go with Gray in Game 1 and Severino on regular rest in Game 2, simply because Tanaka has been so much better at home than on the road. But obviously the Yankees have lost some faith in Gray, and as Girardi said on Wednesday, doing it this way all but guarantees Tanaka getting a home start in Game 5.

It also sets up Sabathia for a potential Game 7, no surprise after the way he pitched against the Indians.

In the end, though, the series is likely to be decided by the bullpens, where I believe the Yankees have a decisive edge, especially the way David Robertson and Chapman are pitching.

The Astros will put that pen to the ultimate challenge, however, as they were the best offense statistically against high-velocity fastballs, even while striking out the fewest times of any team in the big leagues.

Bottom line, however, you can look at all the statistics and matchups you want, but these postseason games often come down to the type of mental toughness that has defined the Fighting Gardners, if you will, throughout this season.

As such theyre a surprise no more, having come of age in September and now October too.

Yankees in seven.