Chapman was also part of the Yankees team that lost to the Astros in the 2017 ALCS. But in the final game of the 2019 ALCS, Chapman threw an off-speed pitch that Altuve hit for a series-ending walk-off home run. As Altuve rounded third base, he clutched at the collar of his shirt, yelling at teammates not to rip off his jersey -- actions that have since raised speculation about whether he may have been wearing some kind of wire that tipped him off to the identity of the forthcoming pitch.
Chapman reiterated Thursday morning that he bore the responsibility for the result, as he was the pitcher who threw the ball. When pressed, he added,with a hint of a smile, "I've seen that video. Alot of people have seen that video. It's a popular video right now.
"And yeah, if you look at his actions, they look a little suspicious. At the end of the day, I just don't know. I can't tell you if he had the sign or didn't have the sign -- I don't know. That's a good question for him and for those guys. I just don't know.
"A lot of people are disappointed with the situation. That's why the commissioner did an investigation. ... Hopefully, they take the right actions. I just feel that they put baseball in a bad spot. A lot of people have suffered because of it, because of what they did, and what came out of it."
In the aftermath of the discipline handed down to the Astros for sign stealing, CC Sabathia and Masahiro Tanaka have said they felt cheated out of the opportunity to play in the 2017 World Series.
"I believe so, too," Chapman said. "It was very close, going back to 2017. With everything, all the details that have come out, it was the extra edge that allowed them to move on."
Chapman complimented former Astros player Marwin Gonzalez, now with the Twins, for Gonzalez's recent apology for what happened in 2017.
"I gotta say, for Marwin to take that step takes a lot, to come out and apologize to everybody publicly," he said. "It takes courage to do that. That's an example for all of those guys. At the end of the day, the findings of the investigation are there, there's no hiding about that. I think they should follow his steps and take some actions.
"At the end of the day, you really have to apologize to the fans. They are the ones watching and seeing everything that has developed. You put baseball in a bad spot, and it's time to take some actions and some responsibility."
Chapman was less forgiving about Astros owner Jim Crane's assertion that stealing signs had no impact on the Astros' championship run.
Crane, Altuve and Alex Bregmanwere made available at a news conference Thursday as the Astros opened spring training in West Palm Beach, Florida.
"I disagree with that," Chapman said. "When you know the signs and you know what's coming, especially at this level of baseball -- we have some of the most talented baseball players in the world -- as hitters, if they have an edge and advantage in knowing what's coming, it's going to make them stronger. Is that the sole reason they won the World Series? I don't know. But what I can say that when you have an advantage like that, it's definitely going to make you a stronger team."
New Yankees ace Gerrit Cole, who pitched for the Astros the past two seasons, said he is ready to discuss his former team if his new teammates inquire.
"I'll just give them an honest answer, which is I had no idea of any of it going on and I didn't see any of it," Cole said. "So, I really don't think I have much to apologize for."
Yankees manager Aaron Boone said he doesn't think it's necessary to talk with Cole about the lingering issue.
"He was there after a lot of the specific things that we know were going on, so no, I don't view it as anything we've got to address with Gerrit," he said.
The Associated Press contributed to this report.
Flashback: Altuve protecting jersey on walk-off HR to send Astros to World Series
Jose Altuve is protecting his jersey as he celebrates taking Aroldis Chapman deep for a walk-off home run to win the AL Championship Series.