CHARLOTTE, N.C. — Keep Pounding.
Ron Rivera preached the Panthers mantra perhaps more than anyone else.
A phrase born in a speech to the team made by former player and coach Sam Mills as he battled cancer.
Now diagnosed with cancer himself, support is coming in from across the Carolinas.
Though he was one of the most well known people in Charlotte for nearly a decade, Ron Rivera had a way with connecting.
There were the charities and events, and then there were the little things. Countless gestures done without fanfare.
"There was a knock on the door and it had Mint," recalled Panthers fan Matt McKenzie. "I mean I recognized the address."
The address was 800 South Mint Street. Bank of America Stadium.
Matt McKenzie was diagnosed with the same type of cancer as Ron Rivera back in 2018 and was about to head in to his first surgery.
Ron Rivera heard McKenzie's story and wrote him a letter.
"It came as a complete surprise," McKenzie said.
In the letter, Rivera let McKenzie know he and the team were thinking of him, and cheering for him, and enclosed the Keep Pounding flag Matt keeps to this day.
"For him to take time out and compose those words and sign it," said McKenzie, "it really meant a lot. It was encouraging."
McKenzie, 43, still keeps the letter on his desk, and it has helped him fight through so many battles.
His cancer originated in his nasal area -- and he is still undergoing surgeries, radiation and chemotherapy.
Rivera signed the letter -- Keep Pounding.
"When it becomes reality for you," said McKenzie, "you really understand what it means. It's not just a football saying, it's a life saying."
Rivera's message still resonates with McKenzie. Now it's his turn.
"Thank you for what you did for me," he said, "and you're in the battle now. Just Keep Pounding. And get better."
Rivera plans to coach during his battle, and will undergo treatment five days per week, for seven weeks.
The Panthers travel to Washington on Dec. 27.