A look at the top contenders at Indian Wells and Miami Masters

The US hardcourt season has just begun with the ongoing Indian Wells Masters this week and the Miami Masters following it later this month. These are the last two ATP Masters 1000 tournaments before the clay season kicks off.

Quite a lot has happened over the past two months with Roger Federer taking the World No. 1 ranking from arch nemesis Rafael Nadal and becoming the oldest No. 1 ranked player in the history.

It will be intriguing to see if he can defend both his titles and repeat the 'Sunshine Double' for the fourth time in his career. The Swiss maestro had a great start to the season, clinching his 20th Slam at the Australian Open and also winning at Rotterdam. He is the favourite to win the title, considering his unbeaten record this season. He will face Argentine Federico Delbonis in his first match at Indian Wells.

Nadal has withdrawn from both the tournaments after being plagued with a hip injury, which forced the Spaniard to pull out of the Mexican Open in February. Hopefully, the Mallorcan will be seen in action on his beloved clay. The Australian, Nick Kyrgios has also pulled out after encountering a right elbow injury.

Novak Djokovic is back after undergoing a successful elbow surgery and will be hungrier to prove his mettle after having a slam less 2017. The former No. 1 has won the Sunshine Double on four occasions and will be looking to replicate the past success again. The Serbian has dropped to World No. 13 in the rankings, his lowest ever since 2008.

The second seeded Marin Cilic will pose a threat to Federer's campaign after his splendid run at the Aussie Open. Cilic has risen to No. 3 in the ATP rankings and will be hoping to win his maiden Indian Wells title.

Grigor Dimitrov, who is seeded third, reached the final of Rotterdam Open, losing to Roger in straight sets. He will be eager to avenge his defeat and move up in the rankings.

The young guns -- Alexander Zverev and Dominic Thiem -- are seeded fourth and fifth respectively. It won't be a surprise to see them holding the trophy in a week's time.

Federer can lose the No. 1 ranking if he fails to reach the semi-finals as Nadal will just lose 90 points. Hence, the Spaniard can reclaim the top ranking even without playing the Masters tournament.

Serena is the favourite in women's draw

On the women's side, Garbiñe Muguruza got ousted by the World No.100 Sachia Vickery in straight sets. The 23- time Grand Slam champion Serena Williams is back after a long hiatus after giving birth to her first child. She made a great comeback, winning her first match of motherhood.

In contrast, the other title favourite Maria Sharapova shockingly lost to Naomi Osaka 4-6 4-6. The defending champion Elena Vesnina will face CiCi Bellis in the opening round and needs to apply a defensive strategy.

Can Federer and Serena continue their dominance and keep defying age barriers? That only time can tell. But it will surely be a compelling month of top tennis.