The primary reason for the Yankees to try Aaron Judge in left field this spring is obvious: It allows the team to play Giancarlo Stanton in the outfield more often, which Stanton believes helps him stay off the injured list.

In some ways, the Yankees go as Stanton goes; when he is healthy and producing, like he was in the first half of last season, the team’s offense can be fearsome. When he is injured, the hole in the middle of the order is obvious.

But why does it have to be right field for Stanton? Why do the Yankees have to mess around with their MVP right fielder?

Or to put it another way, why is Aaron Boone so dead set against playing Stanton in left field at Yankee Stadium?

The surface answer is that there is more ground to cover in left than in right. A slightly deeper dive strongly underscores the point, and makes clear why the Yankees shouldn’t consider playing Stanton in left field other than in select road games.

Teams tend to determine the roominess of their outfield positions not by the dimensions of the walls, but by square footage from dead center to the line. Exact measurements are proprietary, but suffice to say that Yankee Stadium’s left field is on the larger side relative to other parks (so, by the way, is Citi Field).

In order to determine which players are best suited to cover ground, teams have internal data that extends well beyond speed. For example, the Tampa Bay Rays knew that for several years, center fielder Kevin Kiermaier took one of the quickest first steps in baseball. He wasn’t the fastest outfielder in a foot race, but that first step stat helped to explain why he was one of the rangiest.

On a simpler level, sprint speed is a fairly indicative metric. According to the website Baseball Savant, Judge has average sprint speed, which explains why he was able to play a competent center field last year.

Stanton’s sprint speed is in the bottom fifth percentile in MLB, and scouts have always noted that, in addition to that issue, he occasionally takes odd routes to fly balls.

Speed and range would be less important for a left fielder in a ballpark like Coors Field in Colorado, where the ball carries. If the ball is flying over the fence, your left fielder can be fat and slow. The ball does not carry well to left at Yankee Stadium, so a speedy fielder is necessary there.

This helps to explain the Yankees’ preference for Judge over Stanton in left -- and it also adds context to a host of other Yankee left fielder choices.

While the corners are ideally power positions, the Yanks have been willing to sacrifice that tool for the athleticism of Brett Gardner (in his prime, Gardner was an 80 fielder in left on the 20-80 scouting scale, according to one evaluator). They also tried to improve their athleticism in left with the Joey Gallo trade in 2021, and last year were willing to try Oswaldo Cabrera there for that reason.

This also explains why Aaron Hicks, with a combo of athleticism and power (and on-base skills) despite other issues with his game, remains viable to Yankee brass as a left fielder. He can cover the ground.

The one area where the Judge/Stanton alignment hurts the Yankees is the difference in their respective throwing arms. Right field, along with catcher and shortstop, is one of the three positions at which arm strength is most important.

A second baseman does not typically have an above-average arm, so the first half of a relay throw ideally comes from a plus arm in right. Judge has one of the stronger arms in the game, while Stanton’s is just average. On days when Judge plays left, the Yankees will be wasting his greatest defensive asset at a position that does not require it.

Overall, though, the occasional realignment makes sense. Stanton would not effectively cover ground in left, and Judge likely will.

Plus -- and this is of the utmost importance -- the move will keep Stanton out of a DH role that he feels does not give him the best chance to contribute for a full season.