In order to add Cody Bellinger to a jam-packed 40-man roster, the Cubs had to clear some space.

They accomplished that Tuesday afternoon by dealing away left-handed reliever Bailey Horn to the White Sox in exchange for right-hander Matt Thompson.

Horn, 26, originally came to the Cubs in the Ryan Tepera trade with the White Sox in July 2021.

Horn began last season in Double-A before quickly moving up to the Triple-A Iowa bullpen. In total, he pitched to a 4.21 ERA and 1.44 WHIP in 45 games, striking out 78 batters in 62 innings.

The Cubs added Horn to the 40-man roster in November to protect him in the Rule 5 draft. He came to camp this spring as one of the few left-handed options available in the bullpen.

Thompson, 23, was the White Sox’s 2nd round pick in 2019. He spent all of 2023 with Double-A Birmingham, going 6-15 with a 4.85 ERA and 1.57 WHIP in 27 starts. He also struck out 136 batters in 124.1 innings.

The Cubs have a variety of other options to compile an Opening Day bullpen. They at least got some value in the Horn deal, clearing room for Bellinger without designating anybody for assignment.