When summer camp was heating up and Jeremy Jeffress was cranking up his work to prepare for the season, it was impossible to know just what he would provide out of the Cubs bullpen. After all, he struggled in 2019, with the Brewers releasing him in September.

But David Ross knew there was one thing he could count on from Jeffress. It was something that wouldn’t appear on any box score or advanced metric.

“It was real evident early on when he was in camp and then especially summer camp of one, the energy he brings,” Ross said. “Then trying to be the mentor of setting routines, setting expectations.”

As Jeffress’ poise has elevated this season, so has the Cubs bullpen performance. In the last three weeks, the Cubs pen ranks 7th in baseball in ERA (3.45), 6th in opponents’ batting average (.216) and tied for 5th in inherited runners scored percentage (20%).

 A part of the success stems from the moxie Jeffress has induced into this bullpen — the relievers are starting to believe in themselves.

“The guys are just starting to know how good they are and knowing that their stuff plays in the game,” Jeffress said. “I think the younger guys and the veteran guys – the whole bullpen –  is starting to get how good we really are.”

He’s done that since he arrived at the Cubs spring training facility in Mesa, Ariz. He’s been a sounding board and a mentor to the younger relievers and has prided himself on being just as effective for the Cubs in a 1-run game as he is off the field.

As a reliever, it can become difficult to warm up, pause and have to fire it back up at a moment’s notice. Situations in-game can change rapidly and overexerting yourself in a warmup then sitting back down can be problematic. 

“JJ’s kinda coached a lotta those guys, as the season’s gone on, about pacing themselves, how to get almost loose, but not all the way hot,” Ross said. “He’s done a really good job in a lot of areas for us this year and mentoring that young group and creating routines or helping them find their way in the bullpen. I think he’s done a great job with that. Big piece of our bullpen.”

Like a proud parent, Jeffress takes great joy and satisfaction in seeing the bullpen arms succeed for the Cubs.

Rowan Wick, Duane Underwood Jr. and Kyle Ryan are just a few of the relievers who have stepped it up for the Cubs in the bullpen and have the makings of being reliable, long-term pieces as part of the Cubs relief corps.

“[Underwood’s] definitely one of the guys that’s stepping up,” Jeffress said. “He’s very tremendous. He uses his changeup a lot, very well. Him, Rowan Wick, all those young guys are stepping up. Colin Rea, when he’s here, he definitely gives us a couple innings where we can rest up or whatever, spot start. It’s great everyone’s starting to take the ball when their name’s called.”

That mentorship doesn’t apply just to the younger arms, either. His throwing partner, Craig Kimbrel, and he critique one another during their throwing sessions. It’s paying off for Kimbrel, too. In his last 4 outings, he’s pitched a shutout inning each time, striking out 2 batters each time. In many ways, working with Kimbrel has been a dream come true for Jeffress.

“Craig has always been somebody I’ve idolized from back in his days with Boston,” Jeffress said.  “To see him getting back to that guy, it’s fun to watch.”