More dirt domination for Rafa?

MIAMI -- Some of the biggest names in men's tennis passed on the Sony Open this year.

Roger Federer, who has parted ways with IMG, which owns and operates the tournament, coincidentally couldn't find the time in his schedule. We may well never see him here again. Rafael Nadal, after winning in Indian Wells, decided to head straight home to Mallorca, Spain, and take a load off his fragile knees. No. 1-ranked Novak Djokovic actually showed up, but after winning two matches checked out in a straight-sets loss to the ageless Tommy Haas.

"The results show everything," Djokovic said afterward. "As far as I'm concerned, it's definitely the worst match I have played in a long time."

Djokovic won't have a ton of free time on his hands; he's already in Boise, Idaho, for this weekend's Davis Cup quarterfinal against the United States. And then the ATP World Tour's clay-court season officially begins with events in Casablanca and Houston.

It's only nine weeks long, so try to savor the field-leveling effects of the dirt, the prolonged rallies, the marvelous variety of shots.

Most of the top-ranked men will be in Monte Carlo on Tax Day, April 15, for the Rolex Masters. That's when we'll really begin to see how things are lining up for Roland Garros.

In the meantime, here are five things we're hoping to learn over the next couple of months:

1. Will Rafa win his eighth title at Roland Garros in nine years?

Given the precarious state of Nadal's health, this might be the most pressing question of the season. If ever he was going to be vulnerable in Paris, you would think this might be the year.

You would think.

Rafa is a sensational 52-1 at Roland Garros -- the best record, percentage-wise, for any player at any Grand Slam. Think about that for a moment. Better than Bjorn Borg at the French Open (49-2), much better than Federer (66-7) and Pete Sampras (63-7) at Wimbledon.

After a seven-month sabbatical, Rafa returned and reached all four finals in his comeback tour. He's 17-1 this year, the only loss coming to Horacio Zeballos in the final at Vina del Mar. Now, after a month off, he'll be refreshed and recharged.

Unless Robin Soderling comes out of his mysterious retirement -- the Swede, after all, is responsible for the "1" in Rafa's record at Roland Garros -- it looks like Nadal has the best shot to win the crown.

Unless …

2. Is this the year Djokovic completes his personal Grand Slam?

The Serb is very proficient on clay. He's 31-8 at Roland Garros and in recent years there has been an ascending quality to his play there.

Look at this progression: quarterfinals in 2010, semifinals in 2011 and finals in 2012. A year ago, Djokovic lost to Nadal in the finals at Monte Carlo and Rome, and in the final at Roland Garros in four sets. But that was before Nadal's knees sent him to the sideline.

Perhaps, there might be a very slight opening here.

3. What does Federer have left?

As recently as a few years ago, he was the second-best clay courter in the business. He's fallen behind Djokovic, but he's still dangerous.

He won the title in Madrid a year ago, defeating Tomas Berdych, although Djokovic beat him in straight sets at Roland Garros in the semifinals. This year, because the rankings are scrambled, he could see Rafa in the semifinals. If he lost to Nadal in Indian Wells, it's likely it would happen again on clay.

4. Can Murray reach a final at Roland Garros?

It depends on the draw, of course.

Beating Nadal on his favorite court seems like a stretch, but if he's taken out early Murray has the chops to succeed in Paris.

Over the past four years, Murray has made two quarters and a semifinal at the French.

5. Who will surprise us?

Seeing a Spaniard go deep in Paris would not exactly constitute a surprise, but what if it was David Ferrer?

He made the semifinals last year, losing to Nadal. He has won more matches on the ATP World Tour than anyone, by a good margin.

The usual suspects are lurking: Juan Martin del Potro, Jo-Wilfried Tsonga and Nicolas Almagro all made the quarters at Roland Garros a year ago.