Tennis legend Boris Becker has said Novak Djokovic needs to sacrifice family time and focus more on his game if he is to reclaim the top spot in ATP rankings.

Djokovic, who married longtime girlfriend Jelena in 2014, suffered a shocking first-round exit at the ongoing Masters 1000 tournament in Indian Wells — BNP Paribas Open. The 30-year-old was ousted by world no. 109 Taro Daniel of Japan, who clinched a win in three sets — 7-6 (3), 4-6, 6-1.

The 12-time Grand Slam champion had gone through "a small medical intervention" to fix his a long-standing elbow issue that hampered his Australian Open 2018 campaign in January. The Serb though had made an earlier-than-anticipated recovery to compete at Indian Wells but was a shadow of his vintage self in the first round.

He conceded he had felt "weird" and had "completely lost rhythm" during his drab show against Daniel. Djokovic though maintained that he felt "happy" about the quick recovery he had made early in the season.

"He [Djokovic] is a happy family man, he spends a lot of time with his wife and his children but in order to be no. 1 in the world, you have to be 100 percent into the sport all the time," Becker, who had coached the Serb between 2013 and 2016, was quoted as saying by Tennis World USA.

He added: " He is a smart man he knows what he has to do, it is called sacrifice."

Novak Djokovic
File photo of former world no. 1 Novak Djokovic.Cameron Spencer/Getty Images

Djokovic, who was battling for the year-ending no. 1 spot with Andy Murray in 2016, has fallen to the 13th position on ATP rankings following underwhelming performances in the last season.

The former world no. 1 player's only title in 2017 came at the season-opening ATP 250 tournament in Doha. He went on to suffer a series of early exits and was forced to cut short his season following his withdrawal from quarter-final of Wimbledon with an elbow injury.

Notably, seven-time Grand Slam champion John McEnroe had attributed Djokovic's dip in form to the Serb's "off-court issues with the family" while commentating on BBC TV during Wimbledon in 2017.

Djokovic though revealed he had taken McEnroe's comments lightly and said he "does not necessarily agree" with the latter's views.

The Serbian tennis star and his wife had welcomed their second child — Tara in September 2017. The couple also has a three-year-old son, Stefan.