ST. LOUIS -- The Orioles were without Ryan Mountcastle (left wrist), Ramón Urías (midsection discomfort) and, as it turned out, without Rougned Odor (sinus issue) on Thursday afternoon. They saw Austin Hays play through a left hand laceration after being stepped on by three metal spikes. They had a one-man bench. They played a bullpen game, thrusting waiver-claim Bryan Baker into his first career start. And come final pitch, they had just one more arm available behind Félix Bautista, their make-do closer with Jorge López on the bereavement list.

And the O’s won.

“Well,” said manager Brandon Hyde postgame, “it feels good.”

That was the vibe inside the Orioles’ music-filled clubhouse following a nail-biting and nick-inducing 3-2 win over the Cardinals at Busch Stadium in a series-clinching victory that marked Baltimore’s sixth in its past eight games and the eighth in its past 12. The O’s have not lost each of their past four series: a win over Boston, a split with Minnesota, a win over Kansas City and now a triumph over St. Louis.

For as trying as their rebuild has been over the past four years, the O’s (14-18) have not appeared to play baseball anywhere near as well as they are in May (7-4).

“Where we are, organizationally, right now, I think we're very much proud of how we’re playing,” Hyde said. “We’re going to keep playing hard.”

The Orioles knew the fickle position they were in on Thursday. Playing shorthanded, they incited a flurry of roster moves prior to first pitch, spelling Rylan Bannon his Major League debut, adding Denyi Reyes to his first big league roster for pitching cover -- he was the lone arm left available at final out -- and sending down lefty Paul Fry in a bit of a surprise move.

There was clear reasoning for the transactions: simply trying to survive until Friday’s series opener in Detroit.

The O’s instead thrived.

“[Robinson] Chirinos was the only guy on the bench available. Last night, [Anthony] Bemboom was the only guy on the bench available,” Hyde said. “We bullpenned it. It's really difficult to do. That’s a good club. Facing Steven Matz, who we've had problems with in the past. I’m just really happy with our effort.”

There’s a new vibe boasted by this Orioles team. They’re playing looser, the owners of a now-famed Home Run Chain. They’re playing better, with a bullpen and rotation performing well above expectations. And they’re seeming to push past some of the defensive miscues and lapses in focus that plagued them in recent years, at times into double-digit losing streaks.

“It's something that's hard to explain, but it's definitely there,” Trey Mancini said this week. “I mean, everybody feels it.”

It's still just 32 games into the season, and at four games under .500, their record clearly leaves much to improve upon. But this is how the Orioles are biding time before reinforcements arrive.

For the first time in full force, Baltimore is promoting prospects to the Major League roster who figure into long-term plans. No. 10 prospect Kyle Bradish set the tone this series with 11 strikeouts over seven innings in Tuesday’s win. Fellow rookie Tyler Nevin homered in support of Bradish that evening and collected a hit on Thursday. And Bautista, who very well might evolve into Baltimore’s closer in the long term, collected the first two saves of his career on a needed basis, with the series-closing one of the four-out variety.

“Every time I get the ball right now, it just feels like my confidence keeps going up,” Bautista said through team interpreter Brandon Quiniones. “I’m really thankful that they believe in me, that they trust in me. And every time I go out there and I pitch well and I do a good job, that confidence only grows more and more every day.”

All three are competing to remain on a roster that will soon feature top prospects Adley Rutschman, Grayson Rodriguez, D.L. Hall and others whose arrivals will solidify this next phase in Baltimore’s rebuild. Rutschman and Rodriguez, starting in tandem for Triple-A Norfolk on Thursday against the Cardinals’ Triple-A affiliate, showed out while their big league club bore down.

And then there was Bannon, perhaps forgotten in this rebuild given that he was acquired in the 2018 Manny Machado trade -- executed before the current front office took over -- and has taken a winding path to the Majors. His afternoon, with a sensational stop on his first big league chance to rob Nolan Areando and his first hit, was a highlight of the Orioles’ performance as a whole.

So by the time Jorge Mateo doubled off Tyler O’Neill at first base to finalize the win, with Bautista pounding his glove and handshakes promptly exchanged, it didn’t matter if the odds were ever stacked against them.

“[This] means a ton,” Hyde said.