He was asked by sideline reporter Erin Andrews to take him through the last play of the game that won it for Seattle over rival San Francisco, sending the Seahawks to the Super Bowl.
"Well, I'm the best corner in the game," Sherman shouted. "When you try me with a sorry receiver like (Michael) Crabtree, that's the result you're going to get. Don't you ever talk about me."
"Who was talking about you?" Andrews asked.
"Crabtree, don't you open your mouth about the best," Sherman continued.
Sherman apologized to Andrews a little later, saying his anger was not directed at her.
The video and game-winning play is posted on NFL.com's website. After the play, Sherman taunted Crabtree and the Niners' bench and was given an unsportsmanlike conduct penalty.
Crabtree responded by tweeting, "film don't lie... @nflnetwork @espn pull up the tape of that game and show me where this guy is the best? #fake #fake #fake"
Being in the same division, these two teams play twice every year, so this heated rivalry might have just become even more so.