Feisty Federer focuses on fitness

Swiss superstar puts his health ahead of ranking

MIAMI - Roger Federer's impressive return from injury has sparked speculation of his possible return to No 1 in the world, but the 18-time Grand Slam champion said looking after his body is far more important than chasing the rankings.

Since returning from a six-month injury layoff, Federer has won the Australian Open and Indian Wells, and on Monday he cruised past Juan Martin del Potro to move into the fourth round of the Miami Open.