Rookies attempting to play their way onto the roster over here, veterans determined to hold on over there. All these players -- trust us, all of ‘em -- have done the numbers in their heads, and with Opening Day less than a month away, there are lots for teams to sort out in terms of who goes, who stays, etc.

Let’s check out seven interesting roster and position battles:

1) Who will fill out the Yankees’ rotation?

Say this for the Yankees: They’ve got a bunch of intriguing young arms competing for the spots opened up by Luis Severino’s Tommy John surgery and James Paxton’s back surgery. Lefty Jordan Montgomery, who is touching 94 mph this spring, figures to get the No. 4 spot after missing most of 2018 and '19, which leaves the fifth spot a fight between four highly regarded kids: Michael King, Deivi Garcia, Jonathan Loaisiga and Clarke Schmidt.

2) Will Carlson be the Cardinals’ center fielder?

Some teams are reluctant to mention their top prospects. Maybe they don’t want to pressure the kid. Maybe they don’t want to increase expectations. Not the Cardinals. They came to Spring Training hoping top prospect Dylan Carlson would play his way onto the roster, or at least force them into a difficult decision. He’s just 21 years old and has played all of 18 games at Triple-A, but the Cards have seen enough to believe he can contribute in 2020. First, though, he has to play well enough this spring to beat out Lane Thomas, Tyler O'Neill, Justin Williams and others. Go get ‘em, kid.

3) Velasquez vs. Pivetta for a Phils rotation spot

Vince Velasquez against Nick Pivetta is especially interesting in a way that battles for the No. 5 spot usually aren’t. For one thing, expectations could not be higher in Philly after the hiring of Joe Girardi and the signing of Zack Wheeler. For another, both of these guys have big arms and huge promise that has gone mostly unfulfilled. New pitching coach Bryan Price has a history of helping pitchers figure things out.

4) Can Souza Jr. play his way into the Cubs’ outfield?

Few players deserve a healthy, productive season more than Steven Souza Jr. after he missed the entire 2019 season as a result of a gruesome left knee injury suffered in the D-backs' penultimate exhibition game. Only 30, Souza is hopeful of repeating his 2017 season in which he had 30 homers, 16 steals and an .810 OPS for the Rays. He faces a numbers crunch with Kyle Schwarber and Jason Heyward locked into the corner spots, and Albert Almora Jr. and Ian Happ also competing for the final two spots.

5) The Reds have too many outfielders, and that’s a good problem.

This is the kind or problem good teams have, and the Reds have a chance to be very good. With the additions of free agents Nick Castellanos and Shogo Akiyama, the club has to sort out who gets the other two roster spots. Jesse Winker probably will play left field, at least against right-handed pitching, which could leave Nick Senzel, Aristides Aquino and Phillip Ervin fighting for one spot. One thing to keep in mind: Ervin is out of options, which could give him a short-term edge as the Reds would have to pass him through waivers in order to send him to the Minors -- and he’d likely get claimed.

6) How will the Padres sort through their young outfield?

If the Padres end up trading Wil Myers to the Red Sox (as has been rumored but doesn’t feel imminent), then the spring’s most interesting competition will sort itself out. For now, Tommy Pham and Myers are penciled into the corner spots with 23-year-old Trent Grisham expected to play center. That could leave 25-year-old Franchy Cordero or 22-year-old Josh Naylor fighting for the final spot. Or perhaps the Friars figure out how to get all three enough playing time to justify them making the team.

7) The A’s will need some time to sort out their second base situation.

Or maybe it’ll be a combination of starters at the position. Anyway, at least five names are in the mix: Franklin Barreto, Jorge Mateo, Sheldon Neuse, Vimael Machin and Tony Kemp. Barreto is out of options and has an .861 OPS in 290 games at Triple-A. Mateo is also out of options after a solid season at Triple-A (.834 OPS) in 2019. But manager Bob Melvin has promised to give all of them a shot at the job. It’s rare for a contender coming off a 97-win season to have this much uncertainty at a key position.