PHILADELPHIA -- Prior to Wednesday night, it seemed that nearly every decision Phillies manager Rob Thomson made during his club's postseason run had proved to be the correct one.

Yet Philadelphia's season may come down to two pivotal choices within a 24-hour span -- and the first one did not go as planned.

Locked in a scoreless tie in the fifth inning of Game 4 of the World Series on Wednesday night at Citizens Bank Park, Thomson called on left-hander José Alvarado to replace starter Aaron Nola with the bases loaded and nobody out. Alvarado promptly plunked left-handed hitter Yordan Alvarez to force in the game's first run before spiraling en route to a decisive five-run inning.

Though the Phillies' offense was held without a hit by a quartet of Astros pitchers, that fifth inning marked the only blemish for Philadelphia's pitching staff in a 5-0 loss.

"He was just a little bit off," Thomson said of Alvarado. "That's a tough situation to bring him in, but we were just trying to keep the damage to a minimum, I guess. It just kind of got away from us."

Though Nola had thrown only 67 pitches, he wasn’t shocked by the move after allowing seven hits in four-plus innings.

“I mean, I had a feeling, coming out for the third time to face Alvarez,” Nola said. “I had a feeling Alvarado was on right there, especially with no outs and the bases loaded.”

With the best-of-seven series even at two games apiece, that puts the spotlight on Thomson's second major decision: starting Noah Syndergaard in Game 5.

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While Zack Wheeler could have started Thursday on normal rest thanks to Monday's postponement, Thomson has not wavered this week in his decision to use Syndergaard for Game 5. Wheeler's velocity was down a bit from his previous postseason outings in his rocky Game 2 outing, and he's been battling some arm fatigue. The Phillies are hoping that two extra days of rest -- thanks to Friday's off-day -- will get Wheeler back on track.

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But that means Syndergaard will be tasked with setting the tone in the final game of the year at Citizens Bank Park. He will likely be asked to get through only three innings, as he hasn't thrown more than 35 pitches in any of his three outings this postseason (two relief appearances, one start).

Syndergaard's last appearance came in Game 4 of the National League Championship Series, when he tossed 1 1/3 scoreless innings of relief. In his lone postseason start, he held the Braves to one run over three innings in Game 4 of the NL Division Series. Syndergaard was scheduled to start Game 3 of the World Series before the Phils shuffled their rotation following the postponement on Monday.

"I just try to go out there and have success in whichever role they choose to use me in," Syndergaard said.

The same has applied to Alvarado.

Prior to the postseason, he had pitched in the fifth inning or earlier only three times this season -- and each of those came before his May 27 demotion to the Minors and his subsequent resurgence into a shutdown reliever. Thomson has turned to Alvarado in the fifth inning of a tied ballgame twice in the World Series.

In Game 1, it worked. In Game 4, it did not.

"I'll tell you this, this is what I said to Thomps: 'I'm ready for any situation, any given day,'" Alvarado said. "We're here at this stage to win. So anytime he needs me, I'm going to be available."

Though it didn’t pan out this time around, expect the Phillies to follow a similar formula moving forward. Everyone is available out of the bullpen in Game 5, including Seranthony Domínguez, who will be on five days’ rest having not pitched since Game 1 on Friday. Alvarado, Zach Eflin and David Robertson each pitched one inning Wednesday in their first action since Game 1. A Game 5 appearance would be three in a row for Andrew Bellatti, but he threw just nine pitches in his clean inning of Game 4.

With Friday’s off-day, anyone who pitches on Thursday will likely be available again for Game 6 on Saturday in Houston.

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"Everybody's got to be available at this point in the year,” said Eflin, who struck out the side on 12 pitches in the eighth. “This is what we dreamed of. This is why we're here. There's really no time for off-days. We'll all be prepared and ready to go whenever our name is called."

Thomson has called the right name repeatedly over the past month. But it’s the names he calls over the next few days -- and, just as important, when he calls them -- that will determine how the Phillies’ season ends.