This key Cubs offseason signing has been a big problem lately

This offseason, the Chicago Cubs added a pair of veteran arms - Michael Fulmer and Brad Boxberger - to the bullpen mix in free agency. Fulmer's struggles in the late innings early this season are well-documented; and while he's garnered most of the ire of Cubs fans, Boxberger has been an even bigger disaster.

Before we delve too deeply into the numbers, yes, it's only mid-May. That means there's time for both of these guys to turn it around. But, frankly, we haven't been given much evidence to suggest such a dramatic 180 is in the cards. When it comes to Boxberger, his latest outing against the Twins tells you all you need to know about where things currently stand with the right-hander.

Entering with the Cubs already down 8-1, it was as low leverage of a situation one could possibly imagine. But even that didn't help Boxberger get his act together.

Cubs: Even in a blowout loss, Brad Boxberger continues to struggle

He retired the first man he faced, then walked Kyle Farmer. After punching out Willi Castro for the second out of the inning, it looked like Boxberger was going to get through the eighth unscathed. Instead, the wheels totally fell off from there: single, double, walk, single - and that was that.

It was yet another lackluster performance from the right-hander who, even when he's managed clean innings, just hasn't looked sharp this year. His chase rate is in the bottom two percent of the league, his walk rate is in the bottom 20 percent and his average exit velocity and hard hit rate don't paint a prettier picture, either.

His average fastball velocity is down year-over-year and in the month of May (which obviously was impacted by Saturday's blow-up) he has an ERA pushing 10.00. He got off to a decent enough start, but since allowing three runs against the Dodgers in an April 22 outing, he hasn't made it through three consecutive appearances without allowing a run.

Again, a tough three or so weeks isn't enough to write the story of his entire season (at least we'd all better hope it isn't). But getting Boxberger (or Fulmer, but at least one of them) sorted out is a must if you're David Ross and the Cubs. The early returns on the team's two biggest relief additions of the offseason have been, well, not great.