MESA, Ariz. -- The baseball jumped off Cody Bellinger's bat and soared over left-center field at Sloan Park on Thursday morning. As the orb made its way to the grassy berm beyond the wall, the group of Cubs hitters watching from near the home dugout sent some celebratory shouts his way.

True, it was only a live batting practice workout, but this is also the early portion of the spring calendar, the time when hitters are transitioning out of the cage to test their timing against actual pitchers. For Bellinger, in particular, it was an ego-boost blast at the comeback trailhead.

"Any barrel that happens in a live BP is just extra confidence," Cubs hitting coach Dustin Kelly said. "And he felt good. He felt good in the cage this morning, felt good in BP. So to see that happen on the field against a live pitcher, it's just another good thing that happens."

Kelly has known Bellinger since his days as a coach in the Dodgers' farm system. In his first year as Chicago's Major League hitting coach, Kelly is now reunited with the center fielder on an important rebuilding project. The Cubs are hoping to unearth the version of Bellinger that burst onto the big league scene not all that long ago.

Bellinger has endured a three-season tailspin of injuries and inconsistency that led the Dodgers to non-tender the 2019 National League MVP this past winter. With a clear need in center field -- not to mention the need for lefty power -- the North Siders jumped at the chance to add him on a short-term deal.

A return to form for Bellinger would go a long way in raising the ceiling for Chicago's offense.

"It's a big year for him and he's got something to prove," Cubs manager David Ross said. "But it's not a pressure-type thing. It's just like, 'I want to go out there and play baseball. I can't wait to get started.' I think you feel that when you're around him. He's got a great way about him."

Across the board, Bellinger, Kelly and Ross have all used the same terminology when discussing the perceived key to getting his swing back on track. They believe that being "athletic" in the batter's box is the essential element to this project.

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What exactly does that mean?

"I think it's more of a relaxed look in the box," Kelly explained. "He's always [had] kind of a tall, upright stance. But there's a little bit of flexibility in there as he starts to make his move toward the pitcher, and kind of gets into his heel strike."

Kelly added that Bellinger, who is still just 27 years old, is putting in work behind the scenes in the gym and training room to focus on his core and lower half. Over the past few years, Bellinger has had a variety of injury setbacks -- left shin fracture, left rib fracture, left hamstring strain and right shoulder dislocation among them -- which negatively impacted his swing and, in turn, his statistics.

From his initial conversations with the Cubs, Bellinger felt that he was immediately on the same page with Kelly and the training and medical staffs. Bellinger said it was good to focus less on mechanical minutiae and more on what and how he was feeling physically.

"That was a big reason why I wanted to sign here," Bellinger said. "I was speaking about, like, what I feel is right, and they've accepted it, and they agree. And we've just been working towards it. And it's just feeling more natural and getting confident with it."

Kelly's history with Bellinger could also be beneficial in this process.

"Cody and I have spoken the same language since Day 1," Kelly said. "So, he's been able to talk his way through his swing. He understands his body really well and has put a lot of work into it. And I think some of the things that he went through the last couple of years have helped with that."

Across the 2017-19 seasons, Bellinger posted a .928 OPS with a 144 OPS+, meaning he performed 44 percent better than the average MLB hitter. He launched 47 homers with 115 RBIs in his MVP season in '19. In the last three years, though, he totaled 41 homers with a .648 OPS and 74 OPS+ for Los Angeles.

The Cubs will hope that Thursday's home run is a flash of what is coming to Wrigley Field this summer.

"There were some loud noises on that stadium field," Ross said with a smile. "Belli looks like he's in a good spot."