Serena huge favourite to reign supreme in Paris
A fully fit and firing Serena Williams has few challengers but the likes of Azarenka, Muguruza, Kerber and Keys won't make it easy.
Challengers to Serena Williams' throne have proved as fickle as a Paris spring and as the year's second grand slam starts the veteran American is again seemingly in a league of her own.
The 34-year-old's charge to overhaul Margaret Court's record 24 grand slam singles titles may have stalled since she chalked up major number 21 at last year's Wimbledon.
But after fine-tuning her clay court game by winning last week's Italian Open she will begin the defence of her French Open title as the strong favourite.
With twice French Open champion Maria Sharapova suspended pending the findings of an anti-doping hearing after she tested positive for Meldonium in Australia this year, the list of players capable of toppling a fully firing Williams is short.
She has played only three tournaments since losing to an inspired Angelique Kerber in the Australian Open final. But former champion Martina Navratilova says when the big prizes are at stake, the American can be relied upon to perform.
"She hasn't played that much this year, but she came back with a vengeance [in Rome], played great tennis, as well as she has on clay, and she is the big favourite going into the French Open," 18-times grand slam champion Navratilova told the Tennis Podcast in the build-up to Paris.
"When she loses it's an exception... Serena is now healthy, hungry, eager and fresh. She's match-tough after Rome, but still fresh - that's a tough combination, and it will be hard for anyone to beat her."
The main obstacles between Williams and a 22nd singles major which would take her level with Steffi Graff in second place, appear to be Germany's Kerber and former world number one Victoria Azarenka, although both have struggled for consistency.
Kerber suffered first-round defeats in Rome and Madrid, although she did win the title on clay in Stuttgart. Azarenka, ranked five, was back to her best when winning back-to-back titles at Indian Wells and Miami, but doubts have resurfaced. She suffered a back injury in Madrid and lost in the first round in Rome.
"It's just unfortunate that I can't play my best tennis. That's it," Azarenka said after losing to Irina-Camelia Begu in Rome. Others contenders will be Romanian former finalist Simona Halep and Spain's hard-hitting Garbiñe Muguruza.
Muguruza, a semi-finalist in Rome, does not have the trademark clay court game, relying on flat, powerful groundstrokes that could however cause damage at Roland Garros, where the show courts tend to play fast.
There could be an emerging threat from her fellow American Madison Keys, who ran Williams close in the Rome final, and who seems to have developed a taste for clay court action at just 21.
"I think having a couple of top 10 wins this week was really big for me and playing people who have done very well in Roland Garros and just on clay in general," Keys said last Sunday. "But I think the biggest thing is just how calm I have stayed on court and really, even in tough situations, stayed calm and collected and just really focused on my game, and I feel like I'm just playing much smarter tennis."
Three-times champion Williams though, as is usually the case, appears to have the destiny of the tournament on her racket strings.
“I have tried to defend there [in Paris] once, twice, three times before. Didn't quite work so well," she said after winning the Italian Open on Sunday -- her first title triumph in nine months. "But this year is different. I'm going to definitely go in there and I feel more calm and I don't feel stress to, like, have to win. You know, I feel like I just am happy to be out here."
The victory in Italy came at an opportune moment for Williams as she had gone title-less since Cincinnati in the buildup to last year's US Open.
There then followed losses in the finals of the US and Australian Opens and a defeat to main rival Azarenka at Indian Wells.
A fourth round loss to Svetlana Kuznetsova at Miami saw Williams pull down the shutters for a while only for her to roar back to form in Rome.
Asked how relieved she felt to finally get another win -- the 70th of her career -- under her belt Williams replied: "It feels great. But I mean, I have played, let's see, US Open, Australian, Miami, Indian Wells. So it's only four tournaments. So it's not like I was playing every week."