Jed Hoyer and the Chicago Cubs’ front office haven’t been afraid to show some aggressiveness early this season.

They proved that again Monday, as they pulled off a trade with the Seattle Mariners to acquire left-hander Drew Pomeranz, a source confirmed to Marquee Sports Network.

The Athletic’s Ken Rosenthal first reported the news.

The Cubs later made the move official, sending cash considerations to Seattle in the move. Pomeranz is headed to Triple-A Iowa.

Pomeranz, 36, was with Seattle’s Triple-A affiliate and had an upward mobility clause in his minor-league deal, Rosenthal reported.

That clause meant Pomeranz had to be offered to the other 29 MLB teams, and if a team was willing to have him in the majors, the Mariners either had to add him to their 26-man roster or trade him there.

[MORE: Why Cubs are more optimistic about offense compared to 2024 start]

Pomeranz had a 4.66 ERA with the Tacoma Rainiers this season and struck out 14 in 9.2 innings, with opponents hitting .176 against him.

The Cubs would have to make a 40-man roster move to add Pomeranz, although they could move left-hander Justin Steele, who underwent season-ending surgery Friday, to the 60-day injured list to accommodate him. They did clear a spot on their 26-man roster, though, by optioning left-hander Jordan Wicks to Triple-A, per the team’s transactions page.

The Cubs’ bullpen has been a weakness so far this season. They have a 5.19 ERA from their relief corps, which has pitched 86.2 innings — both the fourth-highest marks in baseball.

The Cubs made three moves last week to reshuffle their bullpen. Right-hander Nate Pearson was optioned to Triple-A Iowa, and right-hander Eli Morgan was placed on the 15-day injured list with a right elbow impingement. The team recalled right-hander Daniel Palencia and left-hander Luke Little to take their place. Little later was optioned back to Iowa, with fellow southpaw Wicks recalled.

Hoyer and the front office pulled off moves throughout the 2024 season to try and solve their bullpen issues. They acquired Tyson Miller from the Mariners after he had been designated for assignment, and the right-hander posted a 2.15 ERA in 49 appearances for the Cubs. They also acquired Pearson from the Toronto Blue Jays and signed veteran Jorge López to try and shore up their bullpen midseason.

“When I look at our bullpen, I’m really proud of the work our whole staff did during the season,” Hoyer said at the end of last season.

[MORE: Cubs have best odds to win 2025 World Series, per Baseball Reference]

The Cubs have been aggressive in trying to fix weaknesses within their team this season. Top prospect Matt Shaw struggled in his first taste of the big leagues, and the Cubs optioned him to Iowa both to get him more at-bats and work through some of his holes but also to raise their performance from the hot corner.

Now Hoyer and the Cubs are trying to fix their bullpen problems — adding Pomeranz shows that. He might not seem like the mold of a splashy reliever, but the same could be said about Miller when he was acquired last season. Bullpens are so volatile, and leverage options can emerge from anywhere.

The lefty has some familiarity with Cubs manager Craig Counsell, as he pitched for him in 2019 when he was traded to the Milwaukee Brewers. Pomeranz had a 2.39 ERA with 45 strikeouts in 26.1 innings, 12 holds and two saves for Milwaukee.

Pomeranz joined the San Diego Padres the next winter and posted a 1.62 ERA and a 1.08 WHIP with 59 strikeouts and four saves in 47 appearances across two seasons. His season was cut short in August when he underwent flexor tendon surgery.

It’s been a long, winding road back to the majors since that first operation.

Pomeranz hasn’t appeared in the majors since that 2021 campaign with San Diego. He made five minor-league appearances in 2022 as he recovered, and he underwent another procedure that limited him to seven minor-league appearances in 2023. He spent last season in the minor leagues with the Los Angeles Dodgers and San Francisco Giants, pitching in just eight games.

Pomeranz has a lifetime 3.91 ERA and 1.35 WHIP in parts of 11 big-league seasons.