The Cubs completed a trade Wednesday that closes the books on one of the major moves in recent team history.

The team announced it acquired left-handed pitcher Tom Cosgrove from the San Diego Padres for cash considerations and optioned him to Triple-A Iowa. The Cubs designated right-hander Caleb Kilian for assignment to make room on the 40-man roster.

Kilian had been acquired at the 2021 trade deadline from the San Francisco Giants along with outfielder Alexander Canario for Kris Bryant, the homegrown NL Rookie of the Year, MVP and World Series champion. Canario was designated for assignment during spring training and subsequently traded to the New York Mets. He later was DFA’d by the Mets, and now is with the Pittsburgh Pirates.

[MORE: Cubs put Justin Steele on 15-day IL with elbow injury; Ethan Roberts recalled]

Cosgrove, 28, had been designated for assignment Sunday by San Diego. He was a solid reliever just two seasons ago, posting a 1.75 ERA and 0.97 WHIP with one save and seven holds in 51.1 innings across 54 outings.

But Cosgrove had a difficult 2024 campaign. He missed a month with left elbow inflammation and was funneled between San Diego and Triple-A El Paso. He made 18 major league appearances and had an 11.66 ERA and 1.98 WHIP in 14.2 innings.

Cosgrove is another left-handed relief option for manager Craig Counsell, as the Cubs have only one — Caleb Thielbar — in their major league bullpen, and one more on the 40-man roster in Luke Little. 

Cosgrove throws from a side-arm angle, and relies on a sweeper, sinker and four-seam fastball mix. He threw the sweeper 52.2 percent of the time in 2023, and opponents hit just .153 off that pitch. It still was effective last season — opponents hit .208 off it in 2024.

Kilian, 28, was in Double-A when the Cubs traded for him four years ago. He reached the majors in 2022 but struggled in parts of three seasons in the majors. He made eight appearances with five starts and was 0-4 with a 9.22 ERA and 2.01 WHIP.

Kilian battled injuries in 2024 when he looked poised for a breakout. He missed four months last season with a teres major strain in his shoulder after posting a 1.50 ERA in six Cactus League appearances.

Kilian was granted a fourth option year in 2025 and made one appearance with the I-Cubs this season, allowing six earned runs on three homers in 2.1 innings of work. He was placed on the seven-day injured list Saturday.