LOS ANGELES (AP) -- Retired NFL player Herschel Walker says he's being dropped from speaking engagements because of his relationship with Donald Trump.

In an interview on the "TMZ Sports" TV show, the Heisman Trophy winner and former "Celebrity Apprentice" contestant said he's known Trump "before he became `The Donald.'" Walker said the presumptive Republican nominee is not racist.

Walker told TMZ Sports "just because you build a wall, doesn't mean you're a racist."

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Trump has faced sharp criticism for his statements on immigration and plan to build a wall along the U.S. border with Mexico.