CLEVELAND -- Throughout the utter dominance exhibited by this Guardians bullpen all year long, there has been one question looming in the back of everyone’s mind: How far can manager Stephen Vogt push these talented arms?

Now having played a combined 170 games between the regular season and postseason, the Guardians are on the brink of elimination, and their bullpen appears to be running out of gas after faltering in Friday night’s 8-6 loss to the Yankees in Game 4 of the American League Championship Series at Progressive Field. Cleveland now trails this best-of-seven series, 3-1.

Looking to keep the game at a manageable two-run deficit, Vogt pulled Guardians starter Gavin Williams at just 40 pitches after retiring Gleyber Torres for the first out of the third inning, opting for a bullpen that has a case to be considered the club’s collective MVP of the season.

It started out well with left-hander Erik Sabrowski shutting the Yankees down for 1 2/3 scoreless innings. Right-hander Eli Morgan followed with a scoreless fifth. The sixth, however, was when fatigue began to show.

A one-run deficit with four innings left meant it was time for The Big Four -- Cade Smith, Tim Herrin, Hunter Gaddis and Emmanuel Clase. But once Smith entered in the sixth, it was clear something was off.

One night after a flawless inning in which he blew through Juan Soto, Aaron Judge and Giancarlo Stanton on 10 pitches -- all strikes -- to preserve a one-run lead, Smith faced the same spots in the Yankees’ order on Friday. This time, though, he issued a leadoff walk to Soto, followed by a single from Judge, and two batters later, Smith served up a backbreaking three-run homer to Stanton on a 1-2 fastball that increased New York’s lead to 6-2.

It was a dramatically different Smith from the rookie that lit up the baseball world during the regular season with a heater that ranked in the 100th percentile in fastball run value, per Baseball Savant.

“He was the same Cade as he always is,” Guardians catcher Austin Hedges said. “That Giancarlo Stanton guy is really good at baseball and hits a lot of homers in the postseason. He hit his best pitch. Cade’s fastball was the best pitch in baseball all year. We went down with our strengths and the guy put a good swing on it.”

While it is true that Stanton continued carving out his October legacy by joining Reggie Jackson as only the second Yankees player to hit four or more homers in a postseason multiple times, Smith’s fastball was not what it normally is. His four-seamer averaged 94.0 mph on Friday, with his fastest clocking in at 94.4 and 94.2 on the one hit out by Stanton. Entering the night, Smith’s season average (regular season and postseason combined) was 96.0.

“Everybody is tired,” Vogt said. “I thought Cade showed that a little bit today. But again, even when he's been tired, he's been great for us, and you've got to give credit to them. They put good swings on him, made him work, and just didn't go our way.”

Smith scoffed at the idea that his ineffectiveness may have been a product of being used so often this season.

“I wasn’t in the zone,” Smith said. “I wasn’t competitive. I got behind in the count and I think I threw [Stanton] exactly what I was looking for.”

The reality is, Cleveland’s bullpen is giving all it has. Smith and Herrin -- both of whom pitched Friday -- are the only two pitchers in club history to appear in eight of the first nine games of a postseason. But it’s not just those two. Cleveland’s pitching usage is heavily lopsided in favor of its bullpen.

Here’s a look at the numbers through nine postseason games.

Starters: 9 games, 29 2/3 innings pitched, 3.94 ERA, 34 strikeouts, 14 walks
Relievers: 9 games, 49 1/3 innings pitched, 3.83 ERA, 64 strikeouts, 26 walks

Even Clase -- who entered this postseason viewed as the most dominant closer in the game -- seems to be feeling the effects after he came on in the ninth inning of a tie game on Friday and for a second straight night allowed a pair of go-ahead runs.

Suffice to say, the Guardians will be desperate for innings from starter Tanner Bibee in Game 5 on Saturday night. At the same time, it will be all hands on deck with their backs against the wall, which means they may not have a choice but to keep riding this bullpen that has been their strength all year and hope it can come through one more time after a couple of hiccups over the previous two nights.

“All the back-end bullpen guys, these guys are logging 60 to 80 innings in the regular season and then we’re talking about pitching every single day in the playoffs,” Hedges said. “That’s really, really difficult. But there’s only going to be one team that looks up and says, ‘We responded the right way.’ We plan on winning [Saturday] and being that team.”