Where can the Cubs' bullpen find the boost it needs?

When he addressed the media ahead of the start of the current homestand, Cubs president of baseball operations Jed Hoyer tried to shift the blame for the bullpen woes onto his shoulders — and off of manager David Ross’.

“If I’m being candid, I feel like I’ve put Rossy in tough spot to a certain extent. That’s an area we’ve had so much success with,” Hoyer said Tuesday. “We’ve candidly done a really good job of finding relievers that could come in and throw high-leverage innings at a relatively low cost on one-year deals. We’ve been building bullpens that way for a while. This year, that hasn’t worked yet, and that’s on me. I think that’s put Rossy in a tough spot. That hasn’t lined up the way we kind of expected it to.”

Ross doesn’t deserve zero blame. There have been times this season when criticism of his managerial decisions was warranted. But Hoyer did make an accurate point about the bullpen construction.

In recent seasons, veteran additions have stabilized the backend of the bullpen. That includes the likes of Craig Kimbrel, Ryan Tepera, Andrew Chafin, David Robertson and others. That success might’ve spoiled outsiders, making them believe the Cubs’ bullpen construction was nothing to worry about.

But really, they’ve been fortunate that so many of those low-cost bullpen moves worked out. Relievers are notoriously volatile. When you’re putting together mostly new bullpens every season, hitting a point where the moves don’t work out almost feels inevitable.

That’s how it’s played out so far this season. The Cubs free-agent additions of Michael Fulmer and Brad Boxberger have thus far not worked out. Boxberger, currently on the 15-day injured list with a right forearm strain, only just played catch for the first time Sunday and doesn’t have a clear return date. Fulmer has gotten his chances in high-leverage moments but hasn’t gotten the job done.

Combine that with a group of young relievers without much of a track record of success, and you have a bullpen with no defined roles and few arms who’ve earned Ross’ trust in high-leverage situations. In that sense, struggles aren’t surprising.

“Usually those roles or designations, as guys pitch well, those things become more defined,” Hoyer said. “I think they will over the next few months or so. But yes, to this point, no one kind of grabbed that role and took it to be that guy, especially the ninth inning. And so, as a result, we’ve been matching up more. There’s been times we had the wrong matchup at the wrong time, and it burned us. There’s times when we had the absolute right matchup on paper, and we did it. So we just need that area of the team to stabilize.”

Jeremiah Estrada had been used mostly in low-leverage situations previously, but he had some success and lately has earned more high-leverage opportunities. For example, Ross trusted him to come in and escape a bases-loaded, nobody-out jam Tuesday versus the Mets. The first batter he faced was MLB home run leader Pete Alonso in what FanGraphs’ leverage index said was the highest leverage spot of the night (2.07). He ultimately limited them to just one run, and the Cubs went on to win.

Sunday afternoon against the Reds was a different story. With runners at the corners and two outs in the fifth inning of a 3-3 tie, Ross opted to bring in Estrada to face right-handed hitter Stuart Fairchild. Cincinnati manager David Bell countered with lefty TJ Friedl. In the second-highest leverage spot Cubs pitchers faced on Sunday (the leverage index had it at 2.43), Estrada allowed the go-ahead run to score on a double. Two batters later, in the game’s highest leverage moment (2.98 on the leverage index) he walked in a run to make it a two-run ballgame.

The 8-5 loss wasn’t entirely on Estrada, but he’s the one who got the opportunity to come through in a high-leverage situation early in the game, and he didn’t deliver.

“I think whoever is pitching best, you’re trying to give them the leverage innings,” Ross said. “We tried to leverage those things early, and we lost on the backside. Right now, fifth, sixth inning, trying to get some arms in there so we have some guys like Adbert [Alzolay] and [Mark] Leiter [Jr.] on the backside. We were just not able to get to them with a lead.”

The bullpen overall has been more middle of the pack this season, with its 1.0 fWAR sitting 18th after the game Sunday. But it’s in those high-leverage moments that its flaws have stood out.

Going into Sunday, Cubs relievers had performed like just about the worst high-leverage group in baseball. In those situations, they were allowing the highest average (.354), on-base percentage (.453), slugging (.608), wOBA (.446) and ERA (11.64) in the majors. They had the second-lowest strikeout rate (17.5 percent) and the seventh-highest walk rate (12.4 percent).

Again, bullpens are volatile. The Cubs have some talent in there, and they could break off on a nice stretch. But just hoping things will turn may not be the best course of action.

One lever the front office could pull soon is Codi Heuer’s. He’s made eight rehab appearances with Triple-A Iowa after over a year in recovery from Tommy John surgery (full reconstruction with an internal brace) in March 2022. He’s consistently reaching 97-99 mph with the fastball, and he’s just had three straight scoreless appearances, two of them at one-plus innings.

Heuer is eligible to come off the 60-day IL on Monday, though Ross said Sunday that Heuer is feeling “just a tick off and wants to kind of lock in his mechanics and his strike throwing.” So, they may not activate him right when he’s eligible. But they liked what saw in Heuer’s short time in the big leagues enough that they acquired him in the Kimbrel trade with the White Sox. As soon as he’s feeling right, he should be on his way back to the Cubs.

“The arm, obviously, it’s electric stuff when he’s in the zone, when he’s healthy,” Ross said. “We’ve got to get that thing [the bullpen] figured out a little bit down there, and he would definitely help that if he comes back and is able to be the version of himself that we think he is and he knows he is.”

Outside of him, there are intriguing names in the minors. One of those is Daniel Palencia. On Tuesday, he joined Iowa after a stint on the developmental list, where he worked transitioning to the bullpen. Hoyer said Palencia is up to 102 mph with the fastball, and they’ve been working on simplifying his pitch mix. If he can prove himself quickly at that level, he may get a shot on the big league club sooner rather than later.

But again, we’re talking about adding more young arms to an already struggling bullpen. Hoyer knows that, as encouraging as some of the performances from minor league arms have been, there will be some adjusting to the majors.

“I think we have a lot of young guys that are going to be really quality relievers in the big leagues,” Hoyer said. “But it takes time to get there, and not only time to get through the minor leagues, but also time to maybe take some lumps in the big leagues until you figure it out. And so, we’re going to have to live with some of that.”

There’s no easy solution to fixing the bullpen issues. The Cubs would’ve already done if there was.

But they just need a boost in those high-leverage situations. Where that comes from — and if it comes at all — remains to be seen.

“We’ll continue to work through different matchups and work through potentially adding different guys,” Hoyer said. “We have to get that area right.”