It feels like only yesterday that the Chicago Cubs were celebrating their World Series championship, but like all good parties, that one had to end as the team begins preparing for the 2017 season.

The Cubs officially reported to their complex in Mesa, Arizona for the start of spring training on Tuesday, with players and coaches eager to embrace an unfamiliar role: defending a championship.

Photos: Cubs Spring Training in Mesa

In order to do that, the Cubs will have to rely on some big production out of their most familiar names, like Kris Bryant, Anthony Rizzo, and Jon Lester, but they’ll also be hoping that other players throughout their lineup will step up.

As spring training begins, we’ve identified five players that fans should keep an eye on during Cactus League action.

Albert Almora Jr.

With Dexter Fowler out of the picture, Almora will settle into a platoon role in center field, typically playing against left-handed pitchers while Jon Jay handles things against right-handed starters.

Even with that arrangement currently in place, there is a good chance to believe Almora could force Joe Maddon’s hand and earn more starts in center field. He certainly has the glove for it, and if his hitting can come around, he could be a valuable weapon in the order, especially if he slides into the ninth spot as Maddon will likely bat the pitcher eighth to take advantage of Kyle Schwarber’s presence at the top of the order.  

Willson Contreras

Before last season, the Cubs had a three-headed attack at the catcher position, with David Ross, Miguel Montero, and Tim Federowicz all vying for playing time. As the new season begins, Ross and Federowicz are out of the picture, and Contreras is primed to get the bulk of the starts behind the plate for the Cubs.

For Contreras, the key will be to carry over his approach at the plate from the 2016 postseason. His patient at-bats and clutch hitting were a big part of the reason that the Cubs had a successful lineup in the playoffs, and with his power, he could become yet another incredible weapon in an already stacked lineup.

Jason Heyward

The eyes of the baseball world are going to be fixed prominently on Heyward this season, and with very good reason. In the first season of a lucrative contract with the Cubs, Heyward struggled horribly at the plate, batting a paltry .230 and posting by far the worst numbers of his big-league career.

With an entire offseason to tweak his swing and work on changes, Heyward is going to look to prove that last season’s struggles were a fluke, and that he can be a dominating player on both sides of play in the coming season.

Mike Montgomery

With Jason Hammel gone, the battle for the fifth starter’s position in the Cubs’ rotation is going to be a fascinating one. The two main combatants will surely be Montgomery, who earned his first career save in Game 7 of the World Series, and Brett Anderson, who will be looking to stay healthy as a history of injuries has dogged him throughout his career.

For Montgomery, his opportunity to earn a prominent role with the Cubs cannot be overstated. He will either be a critical swing man in the bullpen or the fifth starter in what was the best rotation in baseball last season, so in either case, a good spring training would give him the kind of momentum that he’ll need during the regular season.

Kyle Schwarber

When ranking the most amazing storylines of the 2016 season, Schwarber’s miraculous return from a torn ACL has to be near the top of the list. He not only came back for the World Series, but he thrived in the hugely pressured environment has he hit .412 and was a dynamic threat at the top of the Cubs’ lineup.

This season, there will still be questions over whether Schwarber can catch or not, but there are two main things that fans need to keep an eye on. First, will his approach remain patient even as he tries to get back into the full swing of things as a player? Second, will his fielding be up to snuff?

All eyes will be on Schwarber, and his success or failure will have a big impact on the Cubs’ chances in the coming year.