Will Federer, Serena, Vika be vulnerable?

Three familiar faces that have been hidden from us for weeks now will reappear in the big Madrid combined event in the coming days: those of Roger Federer, Serena Williams and Victoria Azarenka.

They aren't exactly rushing over to Spain just to grab cool free T-shirts and towels; the fact is all three of those players need to play matches, especially with the French Open quickly coming up on the horizon -- and their most dangerous rivals looking pretty dialed in after a few weeks on the red clay.

Federer is the defending champion in Madrid, but 2012 has an even more long-ago-and-far-away feel than in most cases. Last year, Madrid promoter Ion Tiriac caused an international firestorm when he decided to tear up the familiar and traditional red clay courts in favor of courts that were -- accurately -- described as "smurf blue."

Ultimately, the playing properties of the blue clay worked in Federer's favor, while Rafael Nadal and Novak Djokovic went complaining, slipping and sliding right out of the tournament. But Madrid is back on what you might call their "home court" of red clay this year. That might spell trouble for Federer, who hasn't hit a ball for money since he lost to Nadal in the quarterfinals of Indian Wells a two full months ago -- as long a period (almost to the day) as Federer had off in what is theoretically the end-of-the-year offseason.

In the interim, Federer climbed back up to No. 2 in the rankings (behind Djokovic) without lifting a racket. Nice work if you can get it, eh? But let no one say that the 31-year-old all-time Grand Slam singles champ doesn't deserve a break during the clay season now and then, given how dismally his game matches up with that of his red-clay nemesis, Nadal.

Given Federer's age and his résumé, and the official exemptions he's earned through a combination of those two factors, Federer isn't obliged to play Madrid even though it's a Masters 1000 event. But he probably wants to get some match play before he forgets which side to serve from at deuce. As well, the altitude helps his aggressive game, and he has an excellent history in Madrid since it became a clay-court event in 2009. Federer has been in three of the four finals and one semi. He won twice -- over Tomas Berdych on the blue clay last year, and he got the better of Nadal on the red dirt in 2009.

Serena is also the defending champion in Madrid, and like Federer, she's been cooling her jets; she last played on the green clay in Charleston, where she won the title. The blue clay last year was even slicker and harder than Charleston's Har-Tru surface, and you have to wonder how Serena will like having to defend her title back on the red clay, where her record at Madrid has been lackluster. She's played the event only three times, and won exactly one match during the two red-clay versions -- and that lone victory was an epic 7-6 in-the-third second-round war with No. 43 Vera Dushevina.

On the surface, this suggests that Serena may be vulnerable. But you can go broke quickly betting against Serena, and the altitude will help her game as well.

Then there's Azarenka, who fell from the No. 1 ranking and off our radar with remarkably little fuss or fanfare. Serena wiped up the blue clay with her in last year's final, 6-3, 6-1 -- and that was shortly after Azarenka compiled her 26-match winning streak. The big difference this year may be the red clay, but don't jump to any conclusions -- Azarenka will be rusty after her own two-month layoff (partly because of an ankle injury she sustained at Indian Wells), and she likes faster courts. Azarenka has trouble powering through people on red clay.

The more serious concern for both these MIA champions might be the continuing emergence of Maria Sharapova as a clay-court force. Like their male counterpart Federer, these prodigal WTA champions have good reason to cast anxious glances over their shoulders.