HOUSTON -- After the Houston Astros won Game 6 of the American League Championship Series last week, manager A.J. Hinch spent part of his drive home on the phone with pitcher Lance McCullers Jr., who was disappointed at not being chosen to start Game 7.

"I wanted him to change his mindset because we needed him to be good the next day," Hinch said. "He needed to know going to bed, listen, 'I have a role tomorrow, and my role is going to be pretty big.' I told him, 'You're going to be the pitcher that's going to get the final out while the team celebrates to go to the World Series.'"

Hinch relayed that story to illustrate McCullers' importance to the pitching staff. But in doing so, he also revealed an uncomfortable truth. When Hinch needed a reliever to record the precious, pennant-clinching outs against the New York Yankees, he preferred someone other than hard-throwing closer Ken Giles.

The Astros' confidence in Giles has wavered this October, and for good reason. He has made seven appearances in the postseason and has given up at least one run in six of them. He has faced 40 batters and allowed five walks and 12 hits, including three home runs. He has thrown three wild pitches. His postseason ERA is 11.74.

Giles' latest dud came Saturday night in Game 4 of the World Series against the Los Angeles Dodgers. He entered a tie game in the ninth inning and gave up a first-pitch single to Corey Seager and a five-pitch walk to Justin Turner. Then came Cody Bellinger, who was hitless in 13 World Series at-bats before a seventh-inning at-bat against Astros starter Charlie Morton. He roped an RBI double to left field against Giles.

Three batters. No outs.

Game over.

The Dodgers emerged with a 6-2 victory, squaring the series at two games apiece and guaranteeing it will return to Los Angeles regardless of what happens in Game 5 on Sunday. The 113th World Series has been reduced to a best-of-three sprint, and although Hinch didn't come right out and say it, he could be forced to consign Giles to the role of spectator, just as he did in Game 7 of the ALCS.

"Clearly he's trying to push through the adversity that he's had," Hinch said of the 27-year-old righty. "But to be a back-end reliever you've got to live on that edge of not carrying too long of a memory. You have the ball in your hands at the most critical times because you have the best stuff. He can get outs, and he'll continue to get outs. But it's been tough on him."

And make no mistake, the most recent flop hit Giles hard. Still wearing his workout clothes, he didn't emerge at his locker until almost all of his Astros teammates had showered, dressed and left the clubhouse. Giles took questions for about three minutes and repeated variations of a familiar theme.

"I didn't do my job, plain and simple," he said. "I let the team down."

Giles had a mostly solid regular season. In 63 appearances, he posted a 2.30 ERA, struck out 83 batters in 62⅔ innings and converted 34 of 38 save opportunities. He throws in the upper 90s, occasionally scraping triple digits, and when he's around the strike zone, his stuff can be unhittable.

But Giles doesn't seem to have an answer for why he has struggled in the postseason. In assessing what happened in Game 4, he labeled the hits to Seager and Bellinger as "crappy pitches," seeming to suggest that poor location was to blame. Asked if his problems are mechanical or if he plans to watch video in an attempt to make a more specific diagnosis, he said, "I can't rely on that stuff. It all lies within me. I need to take care of business with myself before I worry about anything else."

Sounds like a closer with a broken psyche, an issue that typically takes more than three games to heal.

"For me, it's about getting ahead [in the count], and it's about executing," catcher Brian McCann said. "He fell behind a little bit tonight and walked a guy. But he's been great for us all season long. We'll turn the page and get ready for tomorrow."

Houston's starting rotation is lined up exactly as the Astros want it. Co-aces Dallas Keuchel and Justin Verlander are slated to start Games 5 and 6, respectively. If the series stretches to a Game 7, Hinch will choose between a rested McCullers and Morton on short rest.

But there's still the matter of navigating the final few innings. Assuming Keuchel and Verlander don't throw complete games, Hinch will need to line up a reliever behind them. Like Giles, Chris Devenski and Will Harris have had their issues in the postseason, too.

"We've got to go out there tomorrow and try to score 10 runs and everything's going to be fine," shortstop Carlos Correa said.

Short of that, the Astros' best late-inning options in a close game are starters. Brad Peacock threw 3⅔ innings of scoreless relief behind McCullers in Game 3 against the Dodgers, and McCullers delivered four shutout innings behind Morton in Game 7 against the Yankees.

Giles said Hinch hasn't treated him any differently over the past few weeks. They speak before every game, and Giles claims to still feel as though he has the manager's trust.

"I'm grateful for him sticking with me, and I know the guys are behind me," Giles said. "I've done a lot for the team, and it's time for me to pick up the weight when they need me the most."

Said Hinch: "It's Game 5 of the World Series coming up, so I think there won't be any need to press any buttons or let them know how big these outs are. We've got to get to 27 outs, and we're going to keep trying to piece it together."

More than ever, it's becoming impossible to keep Giles as part of the puzzle.