TMZ Sports saw Stern in NYC ... and with the debate over the NFL's new rule on the National Anthem protest raging ... we asked the former commish how he'd handle the controversy.

Stern didn't exactly answer the question ... but he did offer a ringing endorsement to the NFL's head honcho.

"I think that commisioner Goodell is doing a great job in difficult circumstances."

He went on to say ... "I think every league needs rules to cover every situation. I don't know what rule I would implement, but there should be a rule that treats everyone fairly, and uniformly."

FYI -- the new regulation has been polarizing. Prez Trump and VP Pence applauded the league ... while others have been super critical of Goodell and the NFL.