The path is clear for Nick Kyrgios' return to the Davis Cup fold after Thanasi Kokkinakis ruled himself out of Australia's looming first-round tie with the United States in Melbourne. Kokkinakis, right, on Tuesday conceded he had no hope of playing in the   March 4-6 grasscourt fixture at Kooyong as he continues his rehabilitation from shoulder surgery. "I won't be ready for Davis Cup. I had surgery three weeks ago and it's all going well, so I'm on the road to recovery right now," Kokkinakis said at Melbourne Park. "I'll be ready to go hopefully in mid-  April." After being a frustrated observer at the Australian Open, the world No.86 will apply an injury-protected ranking to guarantee himself main-draw starts at the season's grand slam events in Paris, London and New York. Kokkinakis's unavailability relieves first-year captain Lleyton Hewitt of a selection headache. The 19-year-old was a fixture during Australia's run to the semi-finals in 2015, while Kyrgios was rested from the   September showdown with Great Britain in Glasgow.