The men's clay-court season is expected to be a battle between the long-ruling King of Clay, Rafael Nadal, and the in-form Novak Djokovic. But there is no firmly established order behind them, which could lead to some different names showing up from week to week. Here are some of the players to keep an eye on:
1. Rafael Nadal
The men's clay-court preview could consist of one word -- Nadal. Ever since 2005, he has dominated this part of the season, typically winning four titles and not losing more than once. A poor clay season for him would be those in 2009 and 2011, when he won three titles and had two defeats. At each of his regular stops at Monte Carlo, Barcelona, Madrid, Rome and the French Open, he has won the title anywhere between seven and eight times. "That makes the situation a little special for me every time I come back to these tournaments, because they are tournaments where I really feel I have great memories and I enjoy," he said.
The only opportunity for the rest of the field might be that he has been a little vulnerable since injuring his back at the Australian Open. The Spaniard has won only one of his next three events -- but that one event was, of course, on clay at the Rio Open in Brazil.
2. Novak Djokovic
The Serb will once again be trying to win the title he wants most -- the French Open. For two years running, Nadal has stood in his way.
Djokovic has the momentum, having won both Indian Wells and Miami. He's challenged Nadal on his surface before -- a 4-hour, 3-minute semifinal in Madrid in 2009, two straight wins at Rome and Madrid in 2011, winning their final in Monte Carlo last year and going up a break in the fifth set of their French Open semifinal. And he's won their past three head-to-head matches, though all were on hard courts.
Djokovic hasn't been as consistent as Nadal through these tournaments, something the Serb says he couldn't do last year because he was targeting the French. "Last year, I put a lot of energy -- mentally, physically and emotionally -- into winning that title. It didn't help much for the tournaments prior to that, like Madrid and Rome. I have a different kind of approach this year," he said.
The question is whether all this will be enough to topple Nadal, which is why their first meeting on the surface this year would be so highly anticipated.
Federer assured his followers last week by tweeting that contrary to perception, he grew up on clay and enjoys playing on the surface. And when he's playing well, his variety and shot-making on it is something to see. A title and four finals at the French Open, as well as six Masters series titles, will back that up.
But the problem for Federer is that his biggest problem -- Nadal -- is a bigger problem on this high-bouncing surface. And even though there isn't the same pounding as on cement, the longer points mean extra wear and tear on his 32-year-old body, which can show by the semifinals and final. Taking a wild card in Monte Carlo means potentially a lot of tennis, but it also gives him some flexibility in his schedule if required.
He's still trying to settle after his unexpected Australian Open win, and there were some shaky performances at Davis Cup two weeks ago. But that has also reduced expectations, making it easier to continue as he was before becoming a Grand Slam champion. And clay is his favorite surface, so with no strong No. 3 behind Nadal and Djokovic, there are opportunities if Wawrinka plays well enough. If he doesn't, his high seeding will open up opportunities for others.
Not an obvious clay-court player, but his enormous game can be very effective. The slower conditions give him time to get to the ball, and he can still hit through the surface. With semifinals at the Australian Open and Miami, it's been a good (but not great) year for the Czech. But he usually produces at least one notable result on the clay.
Not exactly known for consistency, the talented but temperamental Italian has now won 25 of 27 clay matches. If he can maintain that kind of play, he could be one of the significant players on the surface this season. However, there's also a thigh injury and a tendency to throw away matches, both of which were on full display against Nadal in Miami. But either way, he's worth watching -- for the shot-making when he's playing well and the entertainment when he's not.
His good run began with the finals in Rio, continuing with the semifinals in Acapulco and a win over Nadal at Indian Wells. The easygoing but erratic talent says he's working harder now and is also back working with his father, who knows his unusual game. Some solid showings at the next few events might suggest he's finding some consistency at last.
8. David Ferrer
The Spaniard admits that at 32, his fitness and recovery are not quite what they were. That has produced some unusual defeats this season and may also show itself on the clay, though it is still his favorite surface and he will continue to be tough to take out. But he may not be as consistently in the quarterfinals and semifinals.
Andy Murray: Still finding his game after back surgery, looking for a coach and playing on his least preferred surface.
Milos Raonic: Recovered well from injury issues earlier in the year, but if his movement isn't all the way back, he won't win a lot of matches despite his big serve.
Jerzy Janowicz: After a good year in 2013, he has struggled since starting this season with a foot injury.