Rafael Nadal seeks to solidify serve

Novak Djokovic overcame a significant hurdle Sunday in Indian Wells, ending a five-match losing streak in finals to Rafael Nadal. It's the kind of victory that can take a player to another level.

Little has changed in Djokovic's game; rather, he's hungrier than ever. The emphatic result is a 21-0 record in 2011, Hopman Cup included.

The Serb's curious post-match proclamation that Nadal was the greatest ever probably had more to do with his good relationship with the Spaniard, as opposed to, let's say, his rapport with a certain Swiss.

All eyes will be on Djokovic at this week's Sony Ericsson Open.

For the first time since 2006, neither Williams sister is competing in Miami. Kim Clijsters is banged up, and you wonder about the Belgian's motivation, even more so than usual, on a long road trip. Vera Zvonareva lost early at Indian Wells, while three other members of the top 10, Samantha Stosur, Francesca Schiavone and Li Na, are slumping.

Hmm, you think Caroline Wozniacki is the women's favorite?

She may be Slam-less, but "Miss Sunshine" has put up Djokovic-like numbers since the Australian Open, going 14-1. In those victories, she's dropped two sets.

Here are five reasons to watch the unofficial fifth major:

1. Nole's fatigue factor

The way Djokovic has won this season means he won't be tired, physically, in Miami. Sure, Djokovic showed signs of fatigue against Rafa, eyes glazed, but he gets that look time to time, usually overcoming it.

Mentally, though, will the Djoker still have it? His streak must end sometime, and past performances indicate Miami might be the place where he cools.

Last season, Djokovic was felled by Belgium's pocket dynamo, Olivier Rochus, now in the dying embers of his career, in his opener. In 2008, the year Djokovic won a first major in Australia, another opening loss came courtesy of towering South African Kevin Anderson.

Djokovic has a packed clay-court season ahead, starting with the Monte Carlo Masters. He's later scheduled to play three straight weeks, at home in Belgrade, then in Madrid and Rome.

2. Wozniacki's surge

There's little to suggest Wozniacki won't reach the semifinals, at the very least. Shahar Peer, who downed Schiavone, the tour's Energizer bunny, in three hours in Indian Wells, Flavia Pennetta and Jelena Jankovic all have the capability of grinding it out from the back of the court, but no one is doing it better than Wozniacki. That backhand continues to be rock steady.

How Melanie Oudin (remember her?) would love the opportunity to potentially face Wozniacki -- it would mean the Georgia native landing in the third round, something she's failed to accomplish all season. Oudin began well Tuesday, ousting up-and-coming German Julia Goerges. Next for Oudin is veteran Daniela Hantuchova, the 29th seed.

In the Williamses' absence, Oudin is the No. 2 American behind Bethanie Mattek-Sands.

Guess who Mattek-Sands could play in the second round? Wozniacki.

3. A Roger-Rafa semi

With a focused Djokovic around, the days of Roger-Rafa finals are on the wane.

Nadal and Federer surfaced in the same half in Miami, ensuring no final.

The last time they met in a semifinal was four years ago in the Masters Cup. Eliminate the year-end championships, a truncated event, and it dates to the 2005 French Open, when their rivalry had yet to fully develop.

Federer, who claimed he was happy with his game in the wake of losing to Djokovic for a third time in 2011, won't encounter major obstacles en route to the semis. Yes, Marcos Baghdatis and Gilles Simon have beaten the 16-time Grand Slam champion, but both are susceptible to losing early. Simon and top U.S. prospect Ryan Harrison are set to battle in the second round.

Harrison's fellow young gun (albeit two years older at 20), Milos Raonic, could get another crack at David Ferrer, who prevailed in the fourth round at the Australian Open.

4. Clijsters' mood

Clijsters wasn't her usual happy self in Indian Wells. Bothered by a shoulder injury, she was unable to serve 100 percent throughout. With the clay-court season around the corner, the shoulder, which needed attention in Melbourne, too, is a concern.

Clijsters, following her retirement in the fourth round, admitted she wouldn't have played in the desert -- for a few reasons -- if it wasn't mandatory.

At least the defending champion now has her osteopath around.

Most fans, we'd guess, would look forward to a Clijsters-Ana Ivanovic clash in the fourth round, even if the former isn't at full strength. Ivanovic, despite her painful-looking ball toss, gained some momentum in Indian Wells, getting one over compatriot -- but far from a dear friend -- Jankovic.

5. Rafa's serve

It's rare to see Nadal's game deteriorate in the manner it did in the Indian Wells final.

Assured, confident and serving well, Nadal played a high-quality first set against Djokovic.

Then his level dropped, the serve largely to blame.

Nadal served at 25 percent in the second set, with his overall figure resting at under 40. Against Djokovic, who's returning better than anyone else at the moment, it was a worrying development. Only last summer, the serve heavily contributed to Nadal's winning a first U.S. Open and completing his Grand Slam collection.

Nadal could tangle with Alexandr Dolgopolov in the fourth round, and the flashy Ukrainian has a habit of going after second serves.

Dolgopolov's conqueror in Indian Wells, Juan Martin del Potro, may be returning to form faster than anticipated and could play Robin Soderling in the third round.

Big serves and forehands would be the order of the day.

Ravi Ubha writes tennis and soccer for ESPN.com.