Drew Pomeranz's regression should have Cubs searching for another back-end lefty

It’s no secret that the Chicago Cubs will be pursuing reinforcements in the bullpen at the trade deadline. They've been connected to some big arms so far, like Jhoan Duran of the Twins and David Bednar of the Pirates. All of these would be massive improvements to a unit that has seen some regression of late. One thing they could seriously use, though, is another lefty.

A southpaw hasn't been a serious need for a while now. After a brief, shaky start, Caleb Thielbar has been among their most dominant arms this year. The real feel-good story, however, has been Drew Pomeranz. Since his return to the majors in April after four years, he's been a vital part of their success, with a 2.17 ERA and 3.40 FIP heading into Tuesday night's game. That includes his miraculous stretch of 23 1/3 scoreless innings to start his Cubs career.

Alas, the underlying numbers always suggested a regression was coming. Statcast has his expected ERA two points higher at 4.15, and his above league average hard hit and barrel rate also don't inspire confidence in his ability to limit damage. That harsh reality has started to come true recently, with Pomeranz giving up seven earned runs in the six innings since his scoreless stretch. His performance against the Brewers on Tuesday only added to his struggles, as he could only get one out in the fifth and gave up another hit, walk, and run after Colin Rea left.

The Cubs are in no position to be taking chances. After dropping the first two games to the Brewers and looking woefully outclassed in each, they can't afford to keep relying on pitchers like Pomeranz, whose contributions so far have been valuable, but not sustainable. They're quite aware of this fact, too, as evidenced by their decision to designate Chris Flexen for assignment amid his recent struggles.

The Cubs have some options to add a quality lefty in the bullpen

Having Pomeranz as depth is still useful, but it would also be valuable to start looking at other left-handed relievers on the market. The Boston Red Sox have since surged back into contention, taking Aroldis Chapman off the list, and the Orioles have already shipped off Gregory Soto, but there's at least one other obvious option on the table. Danny Coulombe of the Twins has been a subject of rumors lately, although the Cubs have been mostly absent. The big prizes from Minnesota, the aforementioned Duran and Griffin Jax, have gotten outsized attention, but he's been quite impressive as well, with a 1.16 ERA and much better peripherals than Pomeranz.

For a little higher price, there's also Aaron Bummer in Atlanta. Controllable through 2026, his lackluster 4.60 ERA doesn't quite tell the whole story, as he also sports an impressive 55.7 percent groundball rate and a miniucule 4.1 percent barrel rate. Pirates lefty Caleb Ferguson also shows a lot of promise, lacking in strikeouts but ranking among the best in baseball in limiting hard hits and average exit velocity ,and posting a 2.86 expected ERA. Perhaps a bit of one-stop shopping could be done to land him and Bednar, for instance, giving the bullpen a huge upgrade.

The options are fewer to improve from the left side in relief, but pairing one of these arms with Thielbar, with Pomeranz as depth, would give the Cubs some insurance in a group otherwise dominated by righties. At the very least, these should be targets on Jed Hoyer's radar, even if the flashier names and biggest plays will be for right-handed closer types.