In addition, the NFL said the Giants never filed an official complaint with the league.
"The officiating game ball procedures were followed, and there were no chain of command issues," the NFL said in a statement Sunday. "All footballs were in compliance, and no formal complaint was filed by the Giants with our office."
The league issued the statement after Fox Sports reported Sunday that the Giants tested two footballs used in the game in Pittsburgh and questioned their inflation level. Fox Sports reported that the Giants then alerted the league.
"We did not file a complaint," a Giants official told ESPN's Adam Schefter.
"I just know that they said that they felt a little ... I don't know, the PSIs were a little low, so they checked them, and they just let me know they checked them," McAdoo said.
Giants cornerback Eli Apple, who recorded his first career interception and kept the ball as a souvenir, said the ball seemed fine.
"No, I didn't notice anything about it," Apple said.
The Steelers were not notified of any tips or inquiries throughout the week and first heard about it via Sunday's report, a team source told ESPN's Jeremy Fowler.
"I heard about it, but we have absolutely no response," Steelers coach Mike Tomlin said. "We will cooperate fully with whatever New York wants to do in regards to that. We have absolutely nothing to hide. It's a non-story for us."