(CNN) Longtime NBC Sports broadcaster Bob Costas on Monday dismissed the idea that criticism of NFL players protesting during the national anthem has nothing to do with race, calling it "preposterous."

President Donald Trump created a firestorm while campaigning Friday night in Alabama when he suggested NFL owners fire any "son of a bitch" who kneels in protest during the national anthem.

On Saturday and Sunday, the rhetoric continued on Twitter, culminating in widespread protests from NFL players . Team owners and coaches also spoke out

"The reaction is so universal, including from prominent NFL owners who have supported and donated to Trump's campaign and to his inaugural committee," Costas said on CNN's "New Day." "You have not heard a single person within the NFL raise a voice in support of what Trump said."

The issue of players kneeling during "The Star-Spangled Banner" first became controversial last year when then-San Francisco 49ers quarterback Colin Kaepernick took a knee before a game in protest of police brutality and racism.

"What's happened here is that what was already an issue raised primarily by Colin Kaepernick has expanded beyond the specific point that Kaepernick was trying to make -- which is a very valid point -- and now it's become near-universal disgust with the President's insulting remarks," Costas told anchors Alisyn Camerota and John Berman.

Berman noted that around 250 members of the NFL knelt during Sunday's games, leading Costas to remark: "The President has galvanized players of all backgrounds, all beliefs."

Early Monday, Trump again sent out a series of tweets on the issue, similar to those over the weekend. One tweet asserted his opposition to the kneeling protests had nothing to do with race.

The issue of kneeling has nothing to do with race. It is about respect for our Country, Flag and National Anthem. NFL must respect this! — Donald J. Trump (@realDonaldTrump) September 25, 2017

But Costas asked, "Do you want a President of the United States who -- even if you're giving him the benefit of that doubt -- is so tone-deaf to the racial implications of this?"

The broadcaster said, "The idea that this doesn't have something to do with race is preposterous."