At 5:30 p.m. ET today on ESPN, we'll find out who will be filling the American and National League rosters for the 2021 All-Star Game presented by Mastercard, and we certainly do not envy those making the tough decisions on who’s in and who’s out on each league’s 32-man roster.

A reminder: that’s no longer the All-Star managers’ job -- they’ll simply fill out the starting lineups and pick their starting pitchers. Fans voted in the All-Star Game starters on Thursday, and a combination of a player ballot and the Commissioner’s Office pick the Midsummer Classic’s reserves and pitchers. Those picks are subject to some change, of course, as players inevitably get injured or elect not to participate.

But for now, there’s some drama -- because there are simply too many stars in baseball to not have some on the outside looking in. The NL has 24 roster spots left to fill and the AL has 23 (with its starting designated hitter already chosen), and when one scans all the possible choices, it becomes apparent how scarce those open spots are.

• All-Star Game rosters FAQ

Every team needs at least one representative on its league’s roster, bringing another factor into the mix. And, a runner-up finish in the All-Star starters fan vote does not guarantee a reserve spot on the roster; those runners-up go right back into the available pool with everyone else.

Here are some of the biggest position-player stars that could fall victim to that roster crunch.

NATIONAL LEAGUE

First base: Pete Alonso (Mets), Brandon Belt (Giants), Paul Goldschmidt (Cardinals), Anthony Rizzo (Cubs)
The Senior Circuit has no shortage of star power over at first, but it’s strangely been a collective down season nonetheless over there. Entering Saturday, NL first basemen had combined for a .323 weighted on-base average (wOBA), the third-lowest mark in any season of the Integration Era dating back to 1947.

So that leaves the field wide open behind starter Freddie Freeman, and Max Muncy is simply playing too well -- even with his time spent on the injured list -- not to snag a spot somewhere on the roster. Assuming he gets the first backup slot here at first, that leaves four big-time sluggers potentially fighting for one spot.

Second base: Ozzie Albies (Braves), Jake Cronenworth (Padres), Chris Taylor (Dodgers)
The NL only picked one reserve at second base in 2019, and so the competition could already be tight here. Plus, the D-backs could throw a wrinkle into the mix: they need at least one roster representative, and with several stars including Madison Bumgarner, Zac Gallen and Ketel Marte down with injuries, utility man Josh Rojas could be a logical choice to snag a second-base spot.

Taylor, who has been one of the Dodgers’ most valuable contributors, has positional flexibility as an outfielder that could give him a second chance at a spot. But he’ll need to compete with his own teammate, Mookie Betts, of course, in a crowded field fighting for three reserve spots in the outfield.

Shortstop: Javier Báez (Cubs)
Báez is easily one of baseball’s most exciting players to watch, and so on star quality alone you have to seriously consider him. But he also entered Saturday with a .271 on-base percentage and Major League-most 110 strikeouts, somewhat negating his 18 homers that ranked second to All-Star starter Fernando Tatis Jr. among shortstops.

Trea Turner and the resurgent Brandon Crawford have simply enjoyed better all-around seasons. Plus, even with potentially two backup slots at shortstop, this could be a place where Trevor Story is placed as the Rockies’ representative, or Miguel Rojas or Jazz Chisholm as reps for the Marlins (if Trevor Rogers isn’t picked for the pitching staff).

Outfield: Juan Soto (Nationals)
Soto is by no means suffering through a bad season. It’s just not quite the all-time, mythmaking Juan Soto season many of us expected coming into 2021, and that might be just enough to leave him sweating out a spot for Sunday’s announcement. 

Betts seems like a no-doubt pick for one of the three outfield reserve spots, and while Adam Frazier is already representing the Pirates as the starter at second, Bryan Reynolds has done everything he should to earn a spot, too. That would leave Soto battling for the last spot -- and don’t count out Miami’s Starling Marte, St. Louis’ Tyler O’Neill or Los Angeles’ Taylor (again, if he can’t nab a spot at second) as stiff competition there. Soto's teammate, Kyle Schwarber, was also surging with his best Barry Bonds impersonation before he suffered a hamstring strain this weekend.

AMERICAN LEAGUE

Catcher: Yasmani Grandal (White Sox), Gary Sánchez (Yankees)
The AL only carried one backup catcher in 2019, so this was already tight. Look past Grandal’s sub-.200 batting average and you’ll realize he’s brought a ton of value to Chicago with his power and pitch framing. Sánchez brings more star power, of course, and his red-hot June has made him a bright spot amid the Yanks’ tough first half.

This could be one spot, however, that’s affected by the ripple effect of Rays ace Tyler Glasnow’s elbow injury. Glasnow would have been a shoo-in for the AL’s rotation, but apart from him Tampa Bay’s success has been more “sum of its parts” (in true Rays’ fashion) than via standout superstars. So this could be where the AL finds a Rays representative via catcher Mike Zunino, who entered Saturday with 18 homers and 2.2 fWAR -- most among Junior Circuit backstops.

First base: José Abreu (White Sox), Yuli Gurriel (Astros), Matt Olson (Athletics)
This is a who’s who of the AL’s best first baseman, but they happened to share the spot with the All-Star Game’s leading vote-getter in Vladimir Guerrero Jr. That creates a fierce three-way competition for what will likely be two reserve spots. Olson usually has a leg up with the glove, but he entered Saturday exactly average in that department by both Statcast’s ratings (Zero Outs Above Average) and by defensive runs saved. We haven’t even mentioned Jared Walsh (20 homers entering Saturday), who deserves a look here, too.

Third base: Alex Bregman (Astros), Matt Chapman (Athletics), Josh Donaldson (Twins)
Entering Saturday there were three 3-win AL third baseman by fWAR, and they weren’t the three listed above: All-Star starter Rafael Devers, Cleveland’s José Ramírez and Chicago’s Yoán Moncada. Now, whether or not you’d rather see superstars Bregman, Chapman or Donaldson on the roster is subjective; the point remains that there simply aren’t enough spots for a stacked position in the AL this year.

Chapman could get the leg up here by avoiding the injured list (Bregman likely won't be back until after the break, anyway) and, of course, because of his glove. He entered Saturday as baseball’s best overall defender with 15 Outs Above Average.

Designated hitter: Yordan Alvarez (Astros), Nelson Cruz (Twins), J.D. Martinez (Red Sox)
The AL will likely carry a backup DH as it did in 2019, easing the logjam created here by the force that is Shohei Ohtani (who, sadly, doesn’t have his own positional category on the roster -- perhaps he should!). Good luck to whoever has to pick between these three sluggers for the No. 2 slot. Each of them entered Saturday as roughly 2-win players, roughly .300 hitters and with weighted runs created plus (wRC+) totals that were separated by just six points. Two massive sluggers here will probably be left feeling that they should be in.