The world's top two Andy Murray and Novak Djokovic may have pulled out of the tournament with injury, but there is plenty of intrigue ahead of the second Masters event of the year.

Is there any stopping Federer?

What a few months it's been for Roger Federer. After missing most of last year through injury Federer's comeback has been nothing short of miraculous, taking in the Australian Open title in January and then Indian Wells last week.

The Swiss looks fresher than he has done in years and is hitting his backhand better than at any point in his career. He gave a masterclass on that wing against Rafael Nadal in a fourth-round evisceration on Thursday and is now up to No 6 in the world.

The question now is whether Federer should recalibarate his aims for the year and go for broke at the French Open, having hinted that he may need to save himself for Wimbledon by not playing a full clay-court season.

Federer will also be thinking that the No 1 ranking is within his grasp if he can keep dominating, and Murray and Djokovic continue to struggle with form and fitness.

If he plays as he did in Indian Wells, it's hard to see anyone getting close to Federer in Miami.