Twelve-time grand slam winner Novak Djokovic headlines a list of walking wounded at the Australian Open, with the Serb desperate to get back to winning ways after six months out injured.
The former world No 1 is making a tilt at a record seventh Melbourne Park crown, but has some serious rust to shake off if he is to make an impression.
Djokovic has been sidelined since Wimbledon in July, with a Tie Break Tens exhibition event on Wednesday and the Kooyong Classic, where he is drawn to play world No 5 Dominic Thiem, his only chance to test his right elbow injury.
"Finally back in the land down under. I feel ready. Idemo! [let's go]," he tweeted on Sunday, posting a video of himself hitting on Rod Laver Arena.
But after pulling out of an Abu Dhabi tournament late last month and conceding "I still feel the pain", a big question mark hangs over how competitive Djokovic can be.
Having added mercurial former tour player Radek Stepanek to a coaching team spearheaded by Andre Agassi, Djokovic only started hitting tennis balls again in November.
He concedes being sidelined has not been easy, and that missing the US Open last year, the first major he has not played since 2005, was particularly hard.
"It's been a real roller-coaster ride for me for a year-and-a-half with this issue. I've never had surgery in my life, I've never had any major injuries that kept me away from the tour for such a long time," he said.
"I never missed a grand slam in my career. It was a big decision, a big call to make. I couldn't play anymore, there was no choice. It was like, that's it, you can't lift your arm."
A decade after winning his first Melbourne Park title Djokovic has slipped to 14 in the world, his lowest in 10 years, giving him extra drive to make inroads at the season-opening major.
Also coming back from injuries are 2014 champion Stan Wawrinka (knee), big-serving Canadian Milos Raonic (calf and wrist), and world No 1 Rafael Nadal (knee).
At least they remain in contention, unlike Scot Andy Murray (hip) and Japanese star Kei Nishikori (wrist) who both pulled out last week, depriving the tournament of some serious star power.
The mighty Serena Williams, a 23-time grand slam champion, has also decided against rushing into a comeback after giving birth to her first child in September.
One of those who is fully fit, at 36, is defending champion Roger Federer, who says the injuries and pullouts are no surprise.
"A lot of the guys are just touching 30-plus, you know. Back in the day, at 30, a lot of guys were retiring - Edberg, Sampras," he said at the season-ending World Tour Finals in London.
"When somebody is injured at 31, it's like, 'Oh my God, how is this possible?' Actually, it's a normal thing."
Djokovic said he has learned much from his injury, and hoped to use that knowledge to avoid having such a serious problem again.
"I've learned a lesson because I really want to avoid getting to that stage of an injury ever in my career after this," he said.
On the women's side, world No 3 Garbine Muguruza, US Open champion Sloane Stephens and upcoming French star Caroline Garcia have all had injury-hit preparations.
Britain's Johanna Konta, a semi-finalist in Melbourne two years ago, ended her Brisbane International campaign early last week with a right hip injury.
"Hips take a massive beating," Konta said, pointing to the game becoming more physical, with tournaments week in and week out.
"But so do knees, so do shoulders, so do ankles, wrists. Take your pick. Back, lower back. And everything in between."