NEW YORK -- "He's really good."

That was the explanation Astros manager A.J. Hinch gave Monday night when he announced Lance McCullers Jr., not Brad Peacock or Dallas Keuchel on short rest, would be his ALCS Game 4 starter on Tuesday.

"He's a really good pitcher. He's got really electrifying stuff, some of the best stuff in the big leagues," added Hinch. "I don't have to remind all you guys, he was an All-Star to start the year. He has some of the best stuff in the big leagues and we believe in him."

Game 4 was the first start for McCullers in 17 days, since the Red Sox ran him over for five runs in 4 1/3 innings on September 30, in the 161st game of the regular season. His ALDS relief appearance was more of the same -- two runs on three hits and two walks in three innings, again against Boston.

There were questions about what -- and how much -- McCullers could give the Astros in Game 4. He dealt with nagging back trouble in the second half and pitched to an 8.53 ERA in his final seven starts and 31 2/3 innings of the season. Opponents hit .338/.424/.485 against him, which is sightly better than what Buster Posey hit in 2017 (.320/.400/.462). Furthermore, he hadn't thrown more than 83 pitches in a game since July.

Despite that second half performance, the Astros liked the way McCullers matched up with the Yankees, specifically with his hard-to-believe mid-80s curveball that sometimes touches 89 mph Who throws an 89 mph curveball? Pretty much only McCullers.

The Yankees as a team went into Game 4 hitting .212 against curveballs compared to .272 against fastballs during the postseason, which is not an unusual split. During the regular season the MLB average was .218 against curves and .277 against heaters. Considering the curveballs the Yankees have seen this postseason (Corey Kluber, Carlos Carrasco, Trevor Bauer, Justin Verlander, etc.), a .212 average is nothing to sneeze at.

That said, curveballs are much harder to hit than fastballs, and McCullers' curveball is much harder to hit than most curveballs. The Astros had a weapon like that at their disposal, and they opted to use it and use it a lot in Game 4. McCullers threw 43 curveballs among his 81 pitches Tuesday night, and only 10 of those 43 were put in play. Five of the ten were hit into the ground for outs. Only one went for hit. That was McCullers' 81st and final pitch, a hanger to Aaron Judge.

Judge'll do that if you leave a mistake pitch up in the zone. The home run was a bummer ending to an otherwise magnificent outing from McCullers, who held the Yankees to that one run on two hits -- Todd Frazier blooped a third inning single into the triangle in shallow center field -- and two walks in six innings plus one batter. He struck out three and got 10 of his other 15 outs on the ground.

"I haven't been healthy. I've been fighting a lot of things that many people wouldn't understand, and don't really know," said McCullers following Game 4. "I knew what I was capable of. I knew what I expected of myself, and it wasn't a situation where I was like, 'Oh, wow, I'm super happy they're giving me a start, and hopefully I can make it through three,' or whatever the case may be. What I expected was what you guys saw. I expected to compete, be a bulldog and to go out there and try to do the best I could for as long as I could."

The Yankees came back against Houston's bullpen, so McCullers' gem went for naught, though it remains a silver lining for the Astros. McCullers was a question coming into the postseason and his ALDS relief appearance did nothing to assuage those concerns. Then he went out, in a hostile environment in Yankee Stadium, and shoved for six-plus innings to show that yes, he can still be a difference-maker for the Astros. The back injury hadn't taken that ability away.

"He was awesome. And really proud of him because I know how important this start was for him," said Hinch after Game 4. "A very difficult second half for him, and not knowing he was going to be in the rotation, his first relief outing in Boston. And then to come up and pitch with a ton of heart, really one mistake the last pitch of his outing, I'm not even sure it was a mistake, Judge has done that a couple of times this year. Really, really proud of him. I thought he threw tremendously well."    

Unless the Astros decide to start him on short rest in a potential ALCS Game 7 -- a very unexpected decision, that would be -- McCullers will not make another start in the series. He could, however, come out of the bullpen in a potential Game 7, similar to Verlander pitching in relief in Game 4 of the ALDS. In that role, McCullers could be a real weapon, especially given Houston's bullpen issues. 

And, if the Astros do advance to the World Series, McCullers has undoubtedly put himself in position to make a start. The Astros essentially added an All-Star caliber starter to their staff in the ALCS. The back injury really hampered McCullers in the second half and the team wasn't sure where he'd fit in. In Game 4, he showed he's healthy, and that is a positive takeaway from an otherwise disappointing loss.

"A lot of people, I think, were doubting what I was gonna bring to the table. It's hard," McCullers added. "I haven't been healthy. And I'm healthy again. I felt that way, I felt really good, so I'm glad that I was able to go out there and show that."