United States Men's National Team fullback Reggie Cannon said his safety was compromised as a result of being outspoken on racial tensions in the United States.

Cannon, speaking to The Guardian, added that his perception of the U.S. has changed since joining Portuguese side Boavista in September 2020.

Cannon left FC Dallas on a reported €3 million transfer to Boavista in September. Since then the U.S. has endured a turbulent election campaign, followed by an insurrection at the Capitol and the second impeachment trial of a U.S. President in Donald Trump.

He said the abuse included: "Threatening to kill your family, threatening to show up at your house, threatening to do vulgar things to you, that I can't say. It is, unfortunately, part of the society that America is today, especially when Trump was in charge. Now we have moved past that.

Cannon is hopeful that policy in the U.S. will soon shift. "I don't think one man can fix the damage done," he said of President Joe Biden, who has been in office since Jan. 20. "I am talking about racial tension in this country (USA), which is a huge issue which people refuse to admit.

He said his views of America since arriving in Europe have changed "one hundred million percent.

"Looking at the insurrection, Texas freezing over right now... explaining to my teammates what is going on in the country is baffling to me. Explaining the America I have lived in to those who don't live in America, it feels like I am describing medieval times," Cannon said.

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Cannon was frustrated by the reaction of Dallas FC fans to the events following the death of George Floyd in May, and subsequent series of nationwide protests. Fans booed as players took a knee during the national anthem before games.

Dallas FC then asked Cannon to apologise. "It's such a polarizing issue when you get down to it, but we knew we had to do something that would spark conversation and that was the perfect opportunity to do so," the 22-year-old said. "People were against violent protest, they were against peaceful protest, but they weren't against any of that, they were against us speaking, us talking to point out the injustices that my people are facing and have been facing for the longest time."

Cannon said he felt the situation with Dallas was handled terribly and that there were repercussions. "But my career wasn't affected by that and I am able to get to the next level in good time," he added.

Texas, where Cannon spent four years while in the books of FC Dallas, last month endured a brutal winter storm in February that caused more than 70 deaths and left people without power, heat and water amid a pandemic.

Cannon's grandfather, Warren M. Washington, is a renowned scientist specialising in climate change and was awarded the National Medal of Science by former U.S. President Barack Obama.

"Even now, where people still reject climate change in America, I look at the work my grandfather has done to scientifically prove a lot of that exists and it's a threat that is coming -- it's really incredible to see the groundbreaking work he has done, especially as an African American in his time," he said.

"He has broken a lot of boundaries and he has given a lot of motivation to my career, and that's why people can't push me down, because he had to go through it all to get to the level he is; to shake Obama's hand; to win that medal; to prove scientists wrong that an African American can do that."