Green Bay Packers linebacker Clay Matthews has admitted that his tackle on San Francisco 49ers' Colin Kaepernick "wasn't smart", but insists that it was nothing personal.

Matthews spoke before the game of his intentions to hit Kaepernick hard if he was given the chance, and that opportunity came when he leaped into a tackle with the quarterback running out of bounds.

The illegal hit sparked a series of scuffles between the two sides, but Matthews insists that there are no hard feelings between him and the 49ers quarterback.

"First off, it wasn't a very smart play," Matthews told The AP. "I had already committed to hitting the quarterback.

"I guess I should have figured he was going to step out of bounds. But it's nothing personal. I went up to him later and was joking around with him."

The 49ers went on to win the NFL match 34-28, with Kaepernick throwing for three touchdowns and 412 yards.