NEW YORK -- There was some confusion and shock in the Yankees’ clubhouse about an hour before the first pitch of Tuesday’s game, as Jordan Montgomery was hastily informed that a deal had been completed with the Cardinals. The news was so fresh, manager Aaron Boone wasn’t yet sure who else the trade involved.

Eventually, the details filtered out: with Montgomery dealt for outfielder Harrison Bader, the rotation is now essentially set for the rest of the season. It was not the best timing for Jameson Taillon to tie his season high in runs allowed, seeing six men cross the plate on his watch in New York’s 8-6 loss to the Mariners at Yankee Stadium.

“That [trade] hurt, caught me off guard,” Taillon said. “He was definitely a best friend for me here. I’m going to be in his wedding this offseason. We sat next to each other on the flights, shared a love for bourbon and coffee, and we’re pretty much inseparable at the field. It’s going to be tough not having him, for sure.”

Yankees general manager Brian Cashman envisions having right-hander Frankie Montas slide into Montgomery’s rotation spot, meaning the Bombers’ starting five will likely be comprised of Gerrit Cole, Montas, Nestor Cortes, Taillon and Domingo Germán through the next several weeks.  

Luis Severino’s return could supplement the group in mid-September, and there could be appearances by Clarke Schmidt, who is building stamina in the rotation at Triple-A Scranton/Wilkes-Barre.  

“I like our pitching, clearly,” Cashman said. “Top to bottom, there’s a lot of quality there. I’m certainly looking forward to seeing how it plays out the rest of the way.”

Boone said that it was difficult to deliver the news to Montgomery, a deal that “kind of came out of nowhere.” Yet the Yankees see their Deadline haul -- Montas, relievers Scott Effross and Lou Trivino, plus outfielders Andrew Benintendi and Bader -- as one that leaves them better prepared for the playoffs.

“I think we added strong pieces -- we got a frontline starter [in Montas], an All-Star left fielder [in Benintendi] and two really good bullpen arms,” said first baseman Anthony Rizzo, who has homered in four consecutive games.

“I think we’ve added to an already strong unit. Losing guys is tough; Monty was such a great guy in here, a calm presence, and we wish him well for sure. But this is the business side of it. Adding like we did, it’s definitely nice.”

Tuesday’s start represented a stumble for Taillon, who had posted a 1.84 ERA and held opponents to a .189 batting average over his previous three starts since July 16, a rebound from the 8.57 ERA and .323 batting average against he posted over four starts from June 23 through July 10.

Eugenio Suárez and Cal Raleigh hit early homers off Taillon, who was knocked for six runs (five earned) with a season-high four walks over 4 2/3 innings.

“There’s different things I’ve identified as we go along, but right now I’m just chasing it,” Taillon said. “I feel like I’ll figure something out and then I have to chase something else. Hopefully here soon I can just put my head down, nail everything and knock out some good starts in a row.”

That’s true for the rotation as a whole, which was one of the club’s greatest strengths through the first 65 games, when New York’s starters were 28-6 with a 2.71 ERA and a 1.01 WHIP while holding opponents to a .618 OPS. Over the next 39, the starters were 11-9 with a 4.49 ERA, a 1.22 WHIP and a .744 OPS against.

“I think [the rotation] can continue to be a point of strength,” Taillon said. “Obviously there’s been some inconsistency here, led by me. But Gerrit, Montas coming in, Nestor doing what he’s been doing all year, and then Sevy will come back at some point. There’s a lot to like.”

The Yanks slugged back, with Jose Trevino hitting his third homer in the last two games, Rizzo launching his 27th of the season and Josh Donaldson connecting for his first homer -- a game-tying two-run shot in the sixth -- since July 8 at Boston.

Though Lucas Luetge and Albert Abreu were wobbly in relief, Effross and Trivino “did a good job” in their Yankees debuts, according to Boone, who came away from the Deadline with two big thumbs-up for Cashman and the front office.

“I think we’re significantly better, but as I’ve said all along, we’re better in name and paper only,” Boone said. “It’s on us to go and prove it.”