Five things to watch out for in ATP tennis this year

#2 Nadal's quest to become THE all-time greatest player

The king of clay will be looking to become the one true king this season

Rafa currently has 16 grand slam titles to his name, 3 short of Federer who holds the record for most titles. Being 5 years younger than his rival, he has a good chance of breaking the record. Even though he is not expected to achieve the feat this season itself, whether he will be able to reduce the gap is a question the tennis world is curious about.

Until 2014, there was no doubt that Nadal was going to overtake Federer on the list of Grand Slam titles but constant injuries and loss of form made people begin to doubt him.

Nadal, who holds the record for winning at least one Grand Slam title for most consecutive years did not win a single Grand Slam in 2015 and 2016.

He had won at least one Grand Slam title in the years 2005-2014, a span of 10 years but he did not even reach the semi-finals in those two injury-plagued years; 2015 and 2016.

Last year saw his comeback with two titles and a year-end number one finish. These performances have again heated up the discussion of his chase of the Grand Slam record.