Roger Federer makes his long-awaited return to tennis after six months out with a knee injury in Sunday's mixed teams Hopman Cup in Perth ahead of next month's Australian Open. The Swiss 17-time Grand Slam champion has not played a match since July when he tumbled during the final set of a loss to Milos Raonic in the semifinals at Wimbledon. Federer, 35, had surgery for the first time in his career on his left knee in February and after the Wimbledon set-back he did not finish the season, missing out on the US Open and Rio Olympics. During his time out of the game Andy Murray and Novak Djokovic fought out the world No.1 ranking and his Swiss compatriot Stan Wawrinka won the US Open. Federer makes his return with his world ranking down to 16, his lowest since 2001. The Swiss legend, who will partner with Belinda Bencic, said he was looking to ease his way back before the start of the Australian Open in Melbourne on Jan. 16. "I'm really positive about how I'm feeling right now, and practice is going well," said Federer, who was watched by 5,000 fans at a practice session in Perth Thursday. Nick Kyrgios also makes his return in the Hopman Cup, but from a playing ban, after his spectacular meltdown at the Shanghai Masters in October resulted in an initial eight-week suspension. Kyrgios, who will partner with Daria Gavrilova in the Australian team, said he was now focusing on better managing his schedule and time. Federer says he hopes to play for at least another three or four years and that his "mind-set is for the long-term" in assessing his tennis future. Federer said Friday he's not sure of the form he'll produce upon his return, but that retirement isn't part of his thought process. Nadal targets 3 more years Former world No. 1 and 14-time Grand Slam title winner Rafael Nadal believes he can still be a contender at the majors for another three years despite another injury-hit season. The 30-year-old Spaniard, now ranked at nine in the world, shut down his 2016 campaign in October having missed Wimbledon and been forced out of the French Open after two rounds with a wrist injury. But he insists that he can still return to the heady days of his career which saw him capture a record nine Roland Garros titles. "My idea is to stay here for a few more years and I feel enough motivation to be here. I believe that I can compete for important things in the next three years," said Nadal in Abu Dhabi where he is taking part in the Mubadala World Tennis Championship. — Agencies