CHICAGO -- In one month, the Chicago Cubs will take the field as defending World Series champions for the first time since 1909. Sure, it will be only spring training, but the games will have plenty of meaning for a team trying to become the first to repeat since the 1998-2000 New York Yankees won it all three times in a row.

Let’s examine what will matter most when the Cactus League season begins.

Jason Heyward’s swing

What we’ll be watching: After video highlights of his workouts made the rounds on social media this winter and hitting coach John Mallee discussed a plan with reporters at the fan convention, all eyes will be on Jason Heyward's reworked swing this spring. Mallee is relying on Heyward’s ability to return to an old swing -- from 2012 -- which is much easier than trying to incorporate a brand-new one.

After struggling last year, Jason Heyward is going back to his swing from five years ago. Jerry Lai/USA TODAY Sports

Why it matters in March: Heyward can work on his revamped swing in games that don’t matter but will still provide some of the competitive juices he’ll feel once April rolls around. As all parties have stated, it’s harder to change after the season starts, so getting it right during spring training is essential.

Out with the new, in with the old: “He’s trying to mirror the path he had then. It’s not actually making a change to Jason Heyward. It’s just getting him back to who he was. It’s all natural moves for him. It’s all moves he’s done in the past before, so it’s not like adding a leg kick or teaching him to pull the ball more or anything like that. It’s just getting him back to the swing patterns he had when he had success.” -- Mallee

Kyle Schwarber’s defense

What we’ll be watching: We know he can hit, but is he ready to play the field again? When spring games ramp up, it will be close to 11 months since Schwarber's knee surgery.

Being medically cleared is one thing; playing at a high level on defense is another. Even a fully healthy Schwarber wasn’t exactly on a Gold Glove track before he got injured. But that’s understandable because left field isn’t his natural position. That leads to the catching question: Will he?

Why it matters in March: Schwarber’s role in the catching plans is something we’ll see right from the start, as he intends to report with pitchers and catchers next month.

Even though the games don’t count, how well Schwarber moves in the field will be apparent to anyone with a ticket in Arizona. Just don’t tell Schwarber he can’t play defense. He doesn’t take kindly to it.

“Until Theo Epstein tells me I’m a DH and I’m going to get traded, I’m a left fielder and a catcher, and I’m going to keep doing it,” Schwarber said. “It motivates me when people say I can’t play the field.”

It's all about progress: “The benefit from having done what he did during the World Series last year is he's already crossed a mental threshold of knowing he can hit, run and slide … He’s had a few additional months to continue to get stronger, work on higher-level agility elements with goal of playing defense. I'd imagine he'll see his workload increased incrementally, but anticipate him being ready to start the season.” -- ESPN injury analyst Stephania Bell

Keeping the arms fresh

What we’ll be watching: It’s more what we won’t be watching early in spring games, as the Cubs have indicated they’ll take it very slowly with their top arms.

Games start Feb. 25, but you might not see Jon Lester, Jake Arrieta, John Lackey or Kyle Hendricks until about a week into the next month.

Why it matters in March: March sets up April, so the challenge will be keeping arms fresh for the long season while getting them sharp for the start of it. That is even harder to accomplish after they played so deep into the postseason. This year, the WBC throws a wrench into plans as well. With October always in the back of his mind, March is the time for Joe Maddon to remind his starters that they might not always finish what they start during the regular season.

Plan for the long haul: “I went back on all my charts to see what we did [the last time the WBC was played]. Maybe a little less volume early, then get them rolling. Between the WBC and playing in the seventh game of the World Series, we’ve never had this short of an offseason before, so it’s new for all of us. But we’ll come up with a good plan to keep them fresh because we expect another long season.” -- Cubs pitching coach Chris Bosio

Replacing Jason Hammel as the No. 5 starter

What we’ll be watching: The Cubs say Mike Montgomery is the front-runner to fill out the rotation, but now he has some real competition from newly signed lefty Brett Anderson, who has the highest ground ball rate among qualified starting pitchers (65.9 percent) since the start of the 2015 season, according to ESPN Stats & Information. January talk will give way to March production -- and don’t discount someone else emerging; that’s what spring surprises are made of.

Mike Montgomery won't simply be handed the role as the Cubs' No. 5 starter. AP Photo/Kamil Krzaczynski

Why it matters in March: It’s imperative that the Cubs set things up at both the major league and minor league levels going into the regular season. They will need to identify their top depth guys, even after figuring out their No.5 starter. Rob Zastryzny is a good example of a player to watch: If Montgomery and Anderson aren’t Nos. 5 and 6, then Zastryzny could be the guy the Cubs call for a midseason role in the rotation.

Can Anderson help if he’s healthy? That’s a big "if": "When he's healthy he can get you a ground ball. That should play with the Cubs' infield defense but something always seems to come up with him. The Cubs probably aren't relying on him for more than a handful of starts, so it could work." -- a West Coast major league scout

Joe Maddon’s message

What we’ll be watching: Cubs manager Joe Maddon has been tinkering with the right notes to hit for a team attempting to repeat. In reality, "Embrace the Target, Part II" works, considering opposing teams will be "up" anytime the Cubs come to town. But the Cubs manager isn’t one to repeat his themes, and so far, his buzzwords have been "authenticity" and "uncomfortable."

Why it matters in March: Maddon’s message sets the tone for the season. If that sounds like a cliché, just think back to last spring. He had his team ready to roll in April because he convinced them in March that they would be a hunted team in 2016. While many other contenders were feeling their way through the first month, the Cubs were firing on all cylinders.

There’s a T-shirt slogan waiting to happen: “I’m leaning on the phrase or thought of being uncomfortable. I think the moment you get into your comfort zone, after having such a significant moment in your life like that, the threat is that you are going to stop growing -- or not wanting to grow. I really want us to be uncomfortable.” -- Maddon