He said he meant it to honor all veterans, but particularly his brother, a Marine who served in Iraq and was killed in October, 2015, in a transport plane crash while working as a civilian contractor in Afghanistan.
Christopher Ruiz left behind a wife and three young children who live in San Diego, where Matthews got to see them when the Titans played at the Chargers on Nov. 6.
"You could say he's a key to all my success so far," Matthews said of his brother. "That I got in the end zone and did that, it was just a sign to him watching down..."
Matthews said football has done a great deal to distract him since the death of Ruiz.
"The biggest thing for me is just being in my niece's and nephew's lives and my sister-in-law's life as much as I can," he said.
Ruiz was good at football growing up, but once he got to high school he focused on the ROTC and the military, Matthews said.
"I think he was one of my biggest fans," Matthews said. "I talk to people now and they say he used to brag about me a lot. I went a different route.
"It's just normal, you think people are going over there and coming back and then you get the news he's not coming back."
Matthews said his salute was more formal than the sort many players give at big moments in games.
"If you go back and look at my form," he said, "you'll see that's like a real salute, you know?"