Bill Barnwell serves as a senior NFL writer for ESPN.com, breaking down football both on and off the field in unique ways through in-season strategy, offseason moves and additional topics.

He hosts the Bill Barnwell Show podcast with weekly episodes. Barnwell started at ESPN in 2011 as a staff writer for Grantland.

The identical online post circulates whenever the United States exits the Men's World Cup. It claims that if top American athletes all chose soccer, the nation would rule the sport.

At first glance the concept sounds thrilling. Lamar Jackson delivering crosses to LeBron James? Josh Allen surging through the middle? Aaron Judge blocking shots? It would certainly entertain.

Yet would this truly elevate the United States to unmatched success in global soccer? Doubt remains, beginning with the finest player of his era and perhaps history.

The explanation for why super-athletes alone could not carry the United States to World Cup victory stands at 5-foot-7 and 148 pounds.

Lionel Messi excels as an athlete but differs sharply from the typical American stars imagined for a national team filled with top wings and receivers.

In basketball or football, Messi's stature and build would nearly rule him out. Soccer has turned those traits into advantages through a lower center of gravity, rapid short bursts and the ease of evading defenders before shooting, all aided by his compact frame. His vision and precise passing likely developed from competing against larger opponents at La Masia, forming a vital part of his game.

Messi often ranks among the smaller players on the field, yet he is not alone among legends. Diego Maradona stood 5-foot-5 and 160 pounds. Ronaldinho measured 5-foot-10 and 172 pounds. Even Kylian Mbappe, who competed with Messi for scoring marks, is listed at 5-foot-10 and 163 pounds.

While adding elite athletes would improve the USMNT, the notion of instant global supremacy faces limits from physical realities. Height and speed help in some roles but matter less in others, leaving gaps even in a loaded roster.

To illustrate, consider top performers. ESPN FC compiles an annual ranking of 100 players by position. The latest edition featured averages for height and weight across groups including goalkeepers, fullbacks, central defenders, midfielders, wingers and forwards. These figures align closely with broader trends at each spot.

A clear split appears. Goalkeepers, center backs and forwards average 6-foot-2 and over 183 pounds. Fullbacks, all midfielders and wingers average 5-foot-11 and around 160 pounds.

This matches on-field demands. Goalkeepers need reach to guard the goal. Center backs and strikers battle in the air for headers. Taller prospects often move to those positions early.

Even there, extreme height can hinder ball control. In recent seasons across Europe's top leagues, very few outfield players over 6-foot-6 logged significant minutes, and those who did played almost only as strikers or center backs. Global scouting means such athletes are rare at the elite level.

Creators tend to be shorter. Across three seasons in the major leagues, players with at least 10 assists averaged 5-foot-10. Only one reached 6-foot-2. Similar patterns held for chance creation, with shorter players contributing disproportionately.

Taller athletes accounted for 22 percent of minutes but just 12 percent of assists, chances and successful dribbles. While some tall creators succeed, teams rarely build attacks around them in midfield or on the wings.

Soccer players also weigh less than many American counterparts due to constant movement versus the stop-start nature of other sports. This shapes body types naturally.

Justin Jefferson, listed at 6-foot-1 and 195 pounds, would likely drop to 165-170 pounds for soccer. His explosiveness might change without the same muscle mass. Larger players like Ja'Marr Chase at 205 pounds would face even greater adjustments.

Conversely, smaller athletes from other sports might thrive in soccer. Greg Dortch at 5-foot-7 could become a top winger with lifelong training. Allen Iverson at 6 feet might excel as a defensive midfielder. Such cases seem more plausible than oversized stars from other sports dominating soccer at their current sizes.

Recent flag football matches showed the challenge of crossing sports. A U.S. team of non-NFL players defeated squads with stars like Saquon Barkley and Tom Brady by wide margins. Most successful flag players were 5-foot-11 or shorter, highlighting how agility favors smaller builds.

NFL athletes might improve with dedicated practice, yet the point holds: size is not always an asset when rules shift. Soccer rewards an even lower center of gravity.

At the recent World Cup, the largest team by average minutes belonged to Norway at 6-foot-1 and 182 pounds. Other big squads like Bosnia, the Netherlands and Germany exited early. Argentina fielded the shortest team on average. The United States ranked near the middle.

Norway's Erling Haaland at 6-foot-5 and 205 pounds showed how athletic size can dominate as a striker. The United States might gain more at forward, center back and goalkeeper with such athletes, though goalkeeping has long been a strength.

Overall, a lifetime focus on soccer would likely yield more stars like Haaland or Ronaldo. Yet swapping in athletes from other sports would not produce a team capable of collecting multiple World Cups.