Richard Sherman, an NFL player and Stanford University graduate whose $57.4 million contract with the Seattle Seahawks once made him one of the highest paid cornerbacks in the league, took an interest in bitcoin long before it had mainstream attention.

As early as 2014, he was accepting bitcoin as payment for merchandise on his website.

"I had heard about the idea and the premise behind it being kind of like a universal currency — [it could] mitigate concerns about exchanges and stuff like that — and I really thought that was innovative," Sherman tells CNBC Make It. "I could appreciate that idea, and I just wanted to get involved."

He began buying it himself in June, when the price of a single bitcoin was over $2,000 according to historical data from CoinMarketCap.com. He currently also holds other cryptos like ethereum and litecoin.

When bitcoin saw a dramatic spike to a record-breaking $19,000 in December, Sherman says he heard buzz about cryptocurrency everywhere.

Even from his grandmother.

"You couldn't go anywhere when bitcoin was at $19,000 and not hear somebody," he says. "I mean, when I heard my grandma talking about it, I was like, 'Oh yeah this is way too big if my grandma is talking about bitcoin.'

"My grandma doesn't have a computer," he adds with a laugh.