The Yankees and White Sox returned to the field Thursday, but signs of air-quality concerns were all around them.

Smoke was present, if not nearly as present as it was a day earlier.

The crowd for the first game of a doubleheader was sparse, undoubtedly affected by fans avoiding the outdoors.

A White Sox player even took particular precaution regarding the air he breathed.

Chicago third baseman Yoan Moncada wore a tight covering over his mouth and face both at the plate and in the field during the first game of a doubleheader, after Wednesday’s game in The Bronx was postponed because of the air quality.

Moncada kept the covering over his face for his first-inning at-bat, in which he struck out against Luis Severino with two runners on base.

Smoke from Canadian wildfires traveled south and blanketed much of the Northeast and Mid-Atlantic with air that could be harmful to breathe.

The Air Quality Index in The Bronx hovered Thursday afternoon around 150-160, which registered as “unhealthy” — a step up from Wednesday’s air, which registered above 300 and was termed “hazardous.”

“We’ve seen a lot of bizarre over the last few years,” Yankees manager Aaron Boone said before the game. “A little used to it. … Definitely bizarre but familiar territory.”