By Shrivathsa Sridhar MELBOURNE (Reuters) -Novak Djokovic retired injured after losing the opening set of his clash with Alexander Zverev on Friday, sending the German to a first Australian Open final where he will take on defending champion Jannik Sinner for a maiden Grand Slam title.

MELBOURNE, Australia — Of all the praise bestowed on Jannik Sinner after he won his second consecutive Australian Open championship, and third Grand Slam title overall, nothing felt as significant as the comparison made by runner-up Alexander Zverev .

Australian Open tournament director Craig Tiley said he is confident Novak Djokovic will return to the season-opening Grand Slam next year after injury ended the 37-year-old's latest challenge in the semi-finals at Melbourne Park.

Rafael Nadal's uncle and former coach, Toni Nadal, has questioned the legitimacy of Novak Djokovic's thigh injury that forced him to retire during his Australian Open semi-final against Alexander Zverev.

Novak Djokovic simply cannot shake the conspiracy allegations that surrounded him at the Australian Open. The 10-time Australian Open champion went to extreme lengths this week to share photographs of a hamstring strain on his Instagram account after his unexpected withdrawal from the tournament raised concerns.

Aston Villa missed a chance to draw closer to the Premier League's top four on Sunday in a 1-1 draw at home to West Ham United whose Brazilian left back Emerson rescued a point after Jacob Ramsey had got the hosts off to a dream start.