Top 5 contenders for No. 1 ranking in Men's Tennis in 2018

#2 Juan Martin Del Potro

A resurgent Del Potro is looking a class apart this year

Juan Martin Del Potro is nothing less than an enigma. He won his first and only Grand Slam quite a while ago, the 2009 US Open, defeating the great Roger Federer in the final and Nadal in the semi-final, aged just 19.

Since then it has been a tough ride for the Argentine. Recurring wrist injuries have hampered a major portion of his career, and after multiple surgeries Del Potro is back on tour, looking fit and fine as ever and determined to make up for the lost time.

His biggest victory of the season yet came just about a week ago at the Indian Wells final, against old nemesis Roger Federer. He looked promising to complete the 'Sunshine double', but a shock loss to Isner at the Miami semi-final ended his run.

There exists little doubt about his form and fitness though, and a good clay-court season looks overdue. The challenges for Del Potro are not less and he would be wary of that. Having captured the first Masters 1000 trophy of his career, his confidence is sky high.

Clay is not his most natural surface but hardly anyone doubts his talent to succeed on it. His immense power would come handy on the slow red dirt. With his current form, he looks to be the prime challenger to Nadal in the absence of Federer and a struggling Djokovic.

His performance in the coming couple of months would set the tone for the rest of his season as he looks to defend comparably a greater amount of points in the later stages of the tour.

2018 provides Del Potro with his best chance yet to add more Grand Slam titles to his kitty. It would always be a question of 'what if' had he been fit throughout his early career. All is not lost though and we are yet to see the best of the Tower of Tandil. It won't come as a big surprise this time if he demolishes the Big Four to establish his own supremacy on the ATP circuit.