Agustin Calleri of Argentina defeated Albert Costa 6-0, 7-5 Monday at the Madrid Masters. Costa, the 2002 French Open winner, talked of retirement again. ``It's tough because I'm 30,'' said Costa, who had hinted this might be his last season. ``Motivations are weaker. I have my knee, which hurts. You play week after week, for several reasons you become weaker and unsure.