NEW YORK — For about a day, the Yankees could imagine what a healthier September might look like.

Aaron Judge was finally back.

Then Jazz Chisholm Jr. went down.

That is baseball’s particular cruelty in September. One star walks out of the training room and another walks in.

Chisholm has been placed on the 10 day injured list with a sprained right thumb after jamming it while sliding into second base during Tuesday’s 5-3 victory over Colorado. Yankees manager Aaron Boone said Chisholm will perform no baseball activities for seven to 10 days before being reevaluated.

With only 17 games remaining after Wednesday, the calendar becomes almost as important as the diagnosis.

This is not merely about replacing a second baseman.

It is about replacing chaos.

Chisholm has 19 home runs, 55 RBIs and 40 stolen bases in 134 games this season. Those 40 steals are tied for the Major League lead with Tampa Bay’s Chandler Simpson.

More importantly, Chisholm was heating up.

He had hit .381 over his previous 14 games. After an uneven offensive season, his at bats were finally beginning to look like the kind New York hoped to receive during the most important weeks of the schedule.

Then one slide changed the conversation.

The Yankees do have options.

José Caballero started at second base Wednesday, while Anthony Volpe is expected to return from Triple A and has been adding second base to his defensive repertoire. Volpe has also been producing dramatically better offensive numbers in the Minors, giving New York another intriguing possibility.

But replacing Chisholm is not as simple as writing another name next to second base.

His speed changes innings.

A single can become a runner in scoring position. A pitcher becomes distracted. A catcher rushes. An infielder cheats toward the bag.

That pressure becomes even more valuable in October, when runs become harder to manufacture.

There is another reason the injury feels particularly cruel.

Judge just returned.

The Yankees captain missed 84 games because of a stress fracture in his right rib before being activated this week. His return represented the possibility that New York might finally enter the stretch run with its most important offensive presence back in the middle of the lineup.

Instead, the roster exchanged one major return for another major absence.

Trent Grisham is also on the injured list with a right hamstring strain and may not return until October.

Still, panic would be an exaggeration.

The Yankees beat Colorado 6-1 Wednesday, improving to 83-62 and winning for the 15th time in 22 games. Rookie George Lombard Jr. delivered his first career grand slam, Judge collected two hits in his second game back, and Will Warren provided six strong innings.

That performance illustrated why New York remains dangerous.

The roster has depth.

Lombard is emerging.

Judge is back.

Luis García Jr. has provided production since arriving at the deadline.

The pitching staff continues to give the club opportunities.

But the standings leave no room for complacency.

Tampa Bay remains four games ahead in the AL East. New York’s playoff position is strong, but its path to the division title is much less comfortable.

That distinction matters.

Winning the division can change an October path. So can entering the postseason healthy.

For Boone, those goals now compete against each other.

Rush Chisholm and the Yankees risk turning a thumb sprain into a problem that follows him into October.

Wait patiently and New York must play some of its most important regular season games without a player who can influence them in several different ways.

There is no clever solution.

The Yankees need to survive.

That means Judge continuing his build up. It means Lombard continuing to grow quickly. It means Caballero or Volpe absorbing Chisholm’s innings. It means the pitching staff preventing New York from needing five or six runs every night.

And it means hoping seven to 10 days without baseball activities does not become something longer.

The Yankees still control a strong position.

They still have Judge.

They still have October directly in front of them.

But September has delivered another reminder that a postseason roster is never finished until everyone arrives there.

Jazz Chisholm was supposed to be one of the players creating chaos for New York.

Now the Yankees must survive the chaos created by losing him.