CHICAGO — Keegan Akin had a realization Friday: Suddenly, he is the most experienced guy in the bullpen.

With Seranthony Domínguez, Gregory Soto, Andrew Kittredge and Bryan Baker traded prior to Thursday’s MLB deadline, all of the Orioles’ veterans are gone. That leaves just Akin and Yennier Cano as holdovers from the start of the season, with closer Félix Bautista on the injured list with shoulder inflammation. It’s not known if he’ll return this season.

Akin and Cano have over 400 combined major league innings. The other six members of the bullpen? Less than 100.

The Orioles did not enter this three-game series against the Cubs with a plan for managing the bullpen, other than interim manager Tony Mansolino saying the pitching coaches were going to need to “coach their butts off” the rest of the season.

On Friday, the Orioles did not need to go to the bullpen, Trevor Rogers pitching all eight innings in a 1-0 loss. On Saturday, Baltimore had its “top tier” available, using Corbin Martin, Grant Wolfram, Cano and Akin, with Akin getting his first save of the season in a 4-3 win. Sunday, it was Dietrich Enns, Kade Strowd and Akin in a walk-off 5-3 loss.

“For the most part, they threw up zeroes the whole weekend, minus the home run by J.T. [Justin Turner] there at the end of the game, who’s done that a lot in his career in bigger moments than that,” Mansolino said. “Minus the swing right there, you have to feel good about the way the guys handled themselves.”

After the Orioles tied the game in the top of the ninth, Akin allowed a two-run pinch-hit home run to Turner in the bottom of the inning. That came after an error by third baseman Jordan Westburg allowed a runner to reach.

Brandon Young pitched 4 2/3 innings, the two runs scored while he was on the mound unearned. Jeremiah Jackson, who has played less than 10 games in right field in his minor and major league career, mistimed what should have been an easy fly ball for the second day in a row. That allowed Michael Busch to get on base, then advance to third on a flyout and home on a Seiya Suzuki single. The second run scored later in the inning on an Ian Happ double.

“I feel like he couldn’t put people away,” Mansolino said of Young. “I feel like he kept getting to two strikes and then he couldn’t put guys away. He ran up the pitch count a little bit, kind of running through that part of the lineup right there the third time. It got a little murky there in the fifth. We had Dietrich primed and ready to go.”

This left Mansolino with his first real challenge: How does he complete this game with some of his top relievers unavailable?

He went to Enns, picked up on waivers Thursday, first in a 2-2 game. Enns has starting experience, including opening two games for the Tigers this season, so they hoped he would provide length.

“We felt like that was the right guy to get him out of trouble,” Mansolino said.

Except he wasn’t that efficient, and he made it through only 1 2/3 innings before he was yanked after 41 pitches. Enns completed the fifth, then allowed a run in the sixth. He was pulled in the seventh after allowing two runners to get on.

With one out, Strowd, who debuted in May and had pitched 7 2/3 major league innings, took over. He faced just one batter, getting a double play to end the seventh to keep the Orioles within one. Strowd faced the minimum in the eighth as well.

Ryan Noda, acquired on waivers the day prior and making his first appearance with the Orioles, tied the game at 3 in the top of the ninth with an RBI single.

“It’s a spot you dream of as a kid, right?” Noda said. “Ninth inning, two outs, guy on second, down by one. Just trying to do a team at-bat, doing anything I can to get that guy in. Fortunately, today, he left something over the middle of the plate, and I capitalized on it.”

With Mansolino needing someone to try to keep the score tied so they could get to extra innings, he turned to Akin for the second day in a row.

The choice, given the options, made sense. But Dansby Swanson reached right away on Westburg’s error, and Tucker took the first pitch he saw from Akin into the left-center bleachers to win the game for the Cubs.

Would Soto or Domínguez or Kittredge or Baker have given up a walk-off hit like that? There’s no way to know, but this is the new post-deadline reality for the Orioles.

This article has been updated.