Italy Davis Cup winner Jannik Sinner 'heartbroken' over doping accusations

Jannik Sinner triumphs in tennis, faces doping accusations, and leads Italy to Davis Cup victory.

World number one Jannik Sinner said his off-court turmoil over doping accusations was "heartbreaking", after winning the Davis Cup with Italy on Sunday to complete a stellar year.

The 23-year-old won the Australian Open, U.S. Open and ATP Finals before starring for Italy as they claimed a second consecutive Davis Cup triumph, but admitted he is not able to play with a completely clear head.

Sinner is still waiting for the outcome of the World Anti-Doping Agency's (WADA) appeal against his initial exoneration for twice testing positive for traces of the steroid clostebol in March.

"Of course it's in the head a little bit," said Sinner.

"The most important part is all the people who are around me, who know me as a human being trust me -- that's also why I kept playing the level I have.

"Those who know me, I was emotionally a bit down, a bit heartbroken. Sometimes life gives you difficulties and you just have to (deal with) it."

After Italy defeated the Netherlands in the final, Dutch captain Paul Haarhuis said from the outside the doping case against Sinner was impossible to analyse.