SEE IT: Serena, Nadal, Federer, Murray practice ahead of Aussie Open

The Australian Open is less than a week away, and the sport’s top players aren’t wasting any time. They’re hitting the practice courts hard in Melbourne and ensuring that they’re adequately prepared for the first Grand Slam of 2017.

Serena Williams returns to Melbourne as the No. 2 seed behind Angelique Kerber. The world No. 2 was upset by Kerber in last year’s final, but she loves to play here—the American has won the Australian Open six times, and was a set away from winning a seventh a year ago.

The 22-time Grand Slam champion, who will become the Open era’s all-time leader in major singles titles if she wins Down Under, got off to a less-than-stellar start to the season. In her first tournament, in Auckland, she was upset by Madison Brengle in the second round.

World No. 1 Andy Murray is also getting himself ready, as are a pair of legends in Rafael Nadal and Roger Federer.

Murray, a five-time finalist, lost to Novak Djokovic in the 2016 final. He’s lost to the Serb—who’s won the trophy six times and is the two-time defending champion—in four Australian Open finals, and will very well have to get past him in order to hold onto his top ranking. If Djokovic wins the title and Murray fails to reach the semifinals, the former will retake the No. 1 ranking.

Nadal has won the Australian Open once, back in 2009. (Of the four majors, he’s had the least amount of success at this one during his illustrious career.) The 14-time Grand Slam champion, ranked ninth, was beaten by Fernando Verdasco in a thrilling five-setter in the first round a year ago. He reached the quarters in 2015, though, and made it to the final in 2014. Nadal played in Brisbane last week, and looked strong in his first two matches before dropping a close three-set match to Milos Raonic.

And then, of course, there’s Roger. Federer, who has fallen to No. 17 in the world following an injury-plagued 2016, is a four-time champion at the Australian Open, but his last title came seven years ago. His first triumph at the Happy Slam? Way back in 2004.

Federer, 35, hasn’t played an ATP tour match since Wimbledon, but it would be foolish to count him out. Just last year, the Swiss rolled to the semis in Melbourne.

He played the Hopman Cup last week and, despite it being an exhibition, appeared to be back in the swing of things.