Bruising Tailback

Hi.

The following is excerpted from John Grisham's Bleachers. I gathered a bruising tailback was a tailback who bruises the opposing players, or more likely runs almost bruising them, along his way forward; hence, a sturdy tailback. Am I right? Or, does it mean a tailback who get bruised?

Eighty pounds and thirty-five years ago he had been a bruising tailback who had once carried the ball fifty-four times in a game.

Thanks in advance.

Hiro

Sendai, Japan