Atlanta and the White Sox pulled off the first significant trade of the offseason Thursday night, with the Braves acquiring left-handed reliever Aaron Bummer for a five-player package as Chicago looks to rebuild its roster.

The 30-year-old Bummer, whose 6.79 ERA this season was nearly twice his Fielding Independent Pitching number, will add to a deep Braves bullpen. Going back to Chicago are right-hander Michael Soroka -- who was a candidate to be let go by Atlanta on Friday's nontender deadline -- left-hander Jared Shuster, shortstop Braden Shewmake, infielder Nicky Lopez and right-hander Riley Gowens.

Atlanta is banking on a return to form from Bummer, who struck out 78 in 58.1 innings and induced groundballs 58.2% of the time. Bummer stranded a major league-worst 55.4% of runners -- well out of line with his career number and something that portends a return to the first six years of his career, when he posted a 3.03 ERA in 213.2 innings.

With a deal that will pay him $5.5 million in 2024 and includes club options for $7.25 million in 2025 and $7.5 million in 2026, Bummer joins a bullpen that includes closer Raisel Iglesias, left-hander A.J. Minter and a pair of right-handers Atlanta re-signed this winter: Joe Jimenez (three years, $26 million) and Pierce Johnson (two years, $14.25 million).

In new White Sox general manager Chris Getz's first trade, the headliner is Soroka. The 26-year-old, once a top pitching prospect after being chosen in the draft's first round in 2015, twice tore his right Achilles tendon and after returning to pitch in the big leagues in 2023 was shut down in September with forearm tightness. In his breakout 2019 season, Soroka made the National League All-Star team and posted a 2.68 ERA in 174.2 innings. He is due to reach free agency after the 2024 season.

The 25-year-old Shuster, a first-round pick in 2020, debuted in the major leagues with a 5.81 ERA over 11 starts in 2023. In 52.2 innings, he struck out 30, walked 26 and allowed seven home runs.

Shewmake was Atlanta's first-round pick in 2019 and went hitless in four at-bats in his introduction to the big leagues this season after slashing .234/.299/.407 with 16 home runs at Triple-A. A left-handed hitter, Shewmake could compete with right-handers Lenyn Sosa, Romy Gonzalez and Lopez -- the veteran infielder and former Gold Glove finalist at second base whom Atlanta had acquired from the Kansas City Royals at the trade deadline -- for the shortstop job or serve as half of a platoon.

Gowens, 24, is the only player in the deal without big league experience. A ninth-round draft pick out of Illinois this year, he struck out 22, walked six and didn't allow a home run in 15.2 innings after being drafted. Between rookie ball and Low-A, he posted a 1.15 ERA.