This is the time of year when teams start looking particularly closely at their rosters -- when they see what they need, what they can give up and what they can bring in. And, particularly when it comes to trades, they also look at what assets and players they have that are untouchable -- players who aren’t going anywhere.

This week we take a look at the one player on every team who is absolutely untouchable. You might see some guys traded in the next couple of months. But not these guys.

Note: All ages listed are as of Opening Day 2021. We did this exercise last year and last year’s choice is listed with each club.

American League East

Blue Jays: Vladimir Guerrero Jr., 1B (age 22)
The Blue Jays might have “better” players right now, or at least players who have been more productive in their careers than Vlad Jr. has. But he is the face of this franchise and the future of this franchise. If the Blue Jays trade him, what are they, exactly?

Last year’s pick: Guerrero

Orioles: Adley Rutschman, C (age 22)
The No. 1 pick is on the cover of Baseball America this week and remains the vessel for every Orioles fan’s hopes and dreams. They’d more likely trade the mascot.

Last year's pick: Rutschman

Rays: Randy Arozarena, OF (age 25)
The most marketable Rays player since Evan Longoria, they’re already trying to make a movie out of his life. And he still might win the Rookie of the Year Award next year.

Last year's pick: Wander Franco

Red Sox: Xander Bogaerts, SS (age 28)
That seven-year extension kicked off this year, and the Red Sox couldn’t have been happier with it: They’ve got an All-Star shortstop for a long time.

Last year's pick: Rafael Devers

Yankees: Gerrit Cole, RHP (age 30)
It’s tempting to say Aaron Judge here … but he is going to be a free agent over the age of 30 with a history of injury woes awfully soon.

Last year's pick: Judge

AL Central

Indians: José Ramírez, 3B (age 28)
Even with the uncertainty surrounding the Indians, they’re not trading their team MVP.

Last year's pick: Ramírez

Royals: Bobby Witt Jr., SS (age 20)
It might still be another year until he makes the Majors, but they’re building this roster around him for years to come.

Last year's pick: Witt

Tigers: Casey Mize, RHP (age 23)
The Tigers are going to be built around pitching for a while, and even if 2020 didn’t go well, they certainly aren’t going to be selling low.

Last year's pick: Mize

Twins: Byron Buxton, CF (age 26)
They’ve been waiting for him to be healthy and start hitting for power his entire career: They’re not going to bail on him now that he’s doing both.

Last year's pick: Jorge Polanco

White Sox: Luis Robert, CF (age 23)
He may have faded a bit down the stretch, but there’s no question what he’s capable of … and what an incredible talent the White Sox now have at their disposal.

Last year's pick: Eloy Jiménez

AL West

Angels: Mike Trout, CF (age 29)
What would it take to get Mike Trout? Would you have enough players left to fill out a roster around him if you did trade for him?

Last year's pick: Trout

Astros: Kyle Tucker, OF (age 23)
The Astros are in a period of considerable transition, but Tucker finally broke though this year and looks to be, right now, the only outfielder the Astros reliably have.

Last year's pick: Alex Bregman

Athletics: A.J. Puk, LHP (age 25)
He should be recovered from shoulder surgery by the start of next season, and whether he’s in the bullpen or in the rotation, he’ll be at the center of everything the A’s are doing.

Last year's pick: Matt Chapman

Mariners: Kyle Lewis, CF (age 25)
The emergence of Lewis, just crowned the AL Rookie of the Year, is the most exciting thing to happen to the Mariners in years.

Last year's pick: Jarred Kelenic

Rangers: Sam Huff, C (age 22)
The Rangers may clear out all sorts of roster space this year, but Huff (who had a 1.136 OPS and three homers in a brief cup of coffee) looks like a guy who’s going to stick around for a long time … and one they might want to wrap up while they can.

Last year's pick: Joey Gallo

National League East

Braves: Ronald Acuña Jr., CF (age 22)
Considering his reasonable contract … it’s possible Acuña might be the most desired trade chip in baseball.

Last year's pick: Acuña

Marlins: Sixto Sánchez, RHP (age 22)
Remember how bummed out Marlins fans were when they traded J.T. Realmuto? Now they have an ace … and they finished ahead of the Phillies anyway.

Last year's pick: Jesús Sánchez

Mets: Pete Alonso, 1B (age 25)
He didn’t dominate the way he did in 2019, but he’s still the face of this franchise and everything the new Mets want to be.

Last year's pick: Alonso

Nationals: Juan Soto, LF (age 22)
Generally speaking, teams aren’t in the habit of trading future Hall of Famers a few weeks after they turn 22.

Last year's pick: Soto

Phillies: Bryce Harper, RF (age 28)
For all the Phillies’ disappointments since he arrived, you certainly can’t blame him for them.

Last year's pick: Harper

NL Central

Brewers: Christian Yelich, OF (age 28)
The reasonable contract extension they signed him to locks player and team together for many years to come. So what else do they have, moving forward?

Last year's pick: Yelich

Cardinals: Jack Flaherty, RHP (age 25)
The Cardinals' pitching is what got them to the playoffs the last two seasons, and Flaherty is the young, dynamite arm that every team salivates over.

Last year's pick: Flaherty

Cubs: Ian Happ, INF/OF (age 26)
He was probably the best hitter the Cubs had last year (.866 OPS), and his blossoming is a primary reason they won the division in 2020. And unlike Kris Bryant, Anthony Rizzo and Javier Báez, who will be free agents next offseason, Happ is under club control through 2023.

Last year's pick: Báez

Pirates: Ke'Bryan Hayes, CF (age 23)
He’s a blast to watch, which is not something you’ve been able to say about a lot of Pirates this year.

Last year's pick: Mitch Keller

Reds: Jesse Winker, OF (age 27)
Of all their hitters, he’s the one who exceeded expectations in 2020. And he’s still young, with plenty of upside left to come.

Last year's pick: Aristides Aquino

NL West

D-backs: Zac Gallen, RHP (age 25)
The D-backs have to figure out their next step, but whatever they do, Gallen will be a part of it.

Last year's pick: Ketel Marte

Dodgers: Mookie Betts, RF (age 28)
There are obviously many, many players to choose from here, but honestly, let’s not make this more complicated than it needs to be.

Last year's pick: Cody Bellinger

Giants: Joey Bart, C (age 23)
And in 2021, he’ll finally have Buster Posey alongside to help him become the player so many expect him to be.

Last year's pick: Bart

Padres: Fernando Tatis Jr., SS (age 21)
The easiest pick on this list? Has to be, right?

Last year's pick: Tatis

Rockies: Antonio Senzatela, RHP (age 25)
You want to say Trevor Story here, but there’s free agency just around the corner for him. Until the Nolan Arenado situation gets resolved one way or the other, you can’t be sure what’s going to happen here.

Last year's pick: Arenado