Nationals Park in Washington D.C. will always hold a special place for Cubs reliever Michael Rucker.

“There’s always chills a little bit,” the righty said.

It’s where he made his debut on July 30, 2021 against the Nationals — in the aftermath of the trade deadline that saw the Cubs trade away the core of their 2016 World Series winning team.

“Just remembering that and just kinda reliving that in a sense a little bit [and] to have that is cool,” Rucker said.

A lot’s changed in the nearly-two years since Rucker first stepped onto the mound in Washington D.C. The Cubs’ roster looks entirely different — he, Ian Happ and Patrick Wisdom are the only players still on the active roster that appeared in that game and Rucker is the only member from the bullpen that day to still be on the roster (Keegan Thompson and Justin Steele were in Iowa at the time being stretched out as starters and Adbert Alzolay was in the rotation).

For Rucker, personally, plenty has changed, too. Back then, he was a rookie and could get in awe of the moment.

“I think back then it was like facing bigger names — I don’t really get too much of it anymore — but feeling like that starstruck moment where it’s like, ‘Holy crap, I’m facing this guy,’” Rucker said.

Nowadays, he understands himself and the job he must go out and do. That season also provided him the moment where he realized he belonged in the big leagues.

In August of that year, he was tasked with coming in relief of Jake Arrieta, after the Brewers had tagged him for 8 runs on 11 hits in 4 innings of work. Rucker pitched 3 shutout innings, striking out 5 and allowing just 2 hits — he even had his first and only plate appearance of his career, a strikeout to Corbin Burnes.

Those types of moments — like his debut at Nationals Park — become a mental catalog; experiences he can look back on to help him get through his next challenge.

“To have to go through 3 innings, go through the entire lineup and face those guys and do good work against them, [it was] like ‘OK, I can bottle this up and take that out into future outings,’” Rucker said. “That was kinda like the first real, like, ‘OK, I can do this.’”

He gained even more confidence after he had a strong finish to his 2022 season — over the last two months of the season, Rucker pitched in 30.2 innings, allowing a 2.93 ERA and a 1.17 WHIP. This spring, he went under-the-radar – his inclusion on the Opening Day roster seemed like a surprise to outsiders, but to he and the Cubs, there was no question about his inclusion.

“I think this offseason, he put a ton of work in — he owned it,” bullpen coach Chris Young said. “He’s seen how it works and I think he’s learned from all those things, and I think we’re starting to see the fruit of all his work.”

This offseason, Rucker built himself a gym in his garage and worked to build on that finish to the 2022 season. That meant refining the shape of his cutter and slider so that there was more distinction between the two so he could keep hitters off balance. He focused on the mental aspect of pitching, remembering the feel when the cutter has the right power and when the slider has the depth it’s meant to have.

“He’s just done a great job of making them two separate pitches,” Young said. “He’s got so much feel to pitch that when you make just one little suggestion, he can take it and run with it. So, he’s done a really good job of separating those two and using them in the zone and knowing when to get out of the zone with them.”

That, in turn, has led to more confidence with David Ross. In Miami the Cubs’ manager turned to him in one of the highest leverage situations that Rucker has been in — a tie game in the bottom of the 9^th inning. Things didn’t go the way anyone would have hoped for — Rucker allowed a single, hit two batters in a row and then allowed the winning run in on a single without recording an out — but it was a growing moment and one that bounced back from.

Tuesday night against the Nationals, he came in relief of Thompson with a runner on second and one out and stranded the runner to escape the jam.

“Outside of one outing, he’s thrown the ball really, really well,” Ross said Tuesday in Washington. “Filling up the strike zone, can spin it in the strike zone, cut it. He’s done a really nice job. It was nice of him to come in, clean that up a little bit and try to get us back in there.”

It’s another anecdote for his mental log. One that can help him the next time Ross calls on his number in a similar situation.

“I tell my wife this — it’s like the moment of when you jump off a high-dive and you’re [in] the free fall before you hit the water. [It’s] like, ‘OK, here we go,’” Rucker said. “We’ve all been through so much that there’s success that we’ve had and so just to be able to draw on that and recreate it, that’s what we’re here to do — recreate success and have good results and hopefully that leads to wins and playoffs and World Series.”