Former champion Stan Wawrinka only decided on Saturday he would play the Australian Open as he prepares for a return from knee surgery.
The Swiss star has been sidelined since Wimbledon last year, having undergone surgery in August.
There were doubts the 2014 champion would be ready for the year's first grand slam, particularly after he withdrew from the Tie Break Tens exhibition event on Wednesday.
But Wawrinka, 32, confirmed on Saturday he had decided he would play the Australian Open.
"For me, I think the fact that I'm here and I'm going to play the first one, it's a big victory," he said.
"It's the best that I could have dreamed when I had the surgery, is to be here sitting in front of you and to say, 'OK, I'm going to play the first match'. That's something really good from my side, especially from the knee.
"The knee is getting way better. I still have a lot of work to do physically and also tennis-wise to be at my top level. I'm going to take the time I need for that. I know I need to get through those.
"I need to start somewhere anyway. I think here was a good start. It's a good place to start, to get pushed, to see also mentally how I'm going to react, how I'm going to feel when I'm going to be playing matches."
Wawrinka, the ninth seed, will face Ricardas Berankis in the opening round at Melbourne Park.
The three-time grand slam champion said he would need to be cautious on his return.
"It's the most important for me to be careful with the knee. That's why I waited until the last minute to decide if I was going to play or not," Wawrinka said.
"We decided with my team that the practice of today will make the decision if I'm ready or not. For me, most important was to make sure the knee doesn't risk anything.
"There's always a little risk, for sure, especially starting after six months in a match, you're going to get more tight, you're going to get nervous, you're not going to feel as comfortable in a match as in practice.
"But the knee is staying there, so that's the most important."
|Kane disappointed by refereeing decisions despite England win|
|Koepka backed by coach to win more major majors|
|Rybarikova ousts Pliskova in Birmingham, seeds fail in Mallorca|
|Kane: England players had flies in our mouths|
|Lemar signs Atletico deal|
|Griezmann renews Atletico Madrid contract after rejecting Barcelona|
|Captain Kane comes good to heighten England´s aura of optimism|
|Wawrinka and Cilic cruise through at Queen´s|
|Saudi Arabia team safe after aircraft´s ´technical failure´|
|Courtois: Panama made unnecessary tackles|
|Thiem makes winning start on Halle grass|
|Tunisia 1 England 2: Captain Kane saves Three Lions|
|Trotz resigns as Capitals coach after Stanley Cup win|
|You´ll see the best of Hazard later - Eden predicts strong World Cup|
|Mickelson made statement over ´outrageous´ conditions, says Cowen|
|France will grow again - former coach Saint-Andre sees positive signs for Les Bleus|
|Lewandowski sets an example - Nawalka talks up Poland star|
|Runners and Ryders: Koepka shines at Shinnecock Hills as European list sees major changes|
|Mature and patient Belgium show success could be on horizon|
|Salah facing fitness test ahead of Russia v Egypt|
|South Korea´s Park has suspected hamstring tear|
|Sweden hero Granqvist full of praise for VAR|
|Iran v Spain: Isco impressed with Hierro´s seamless adaptation|
|Belgium 3 Panama 0: Mertens magic sets up Group G win|
|Jorginho has ´five-year Man City deal waiting´|
|Wolves sign Portugal goalkeeper Patricio|
|Pekerman criticises Barcelona´s treatment of Yerry Mina|
|Neymar misses Brazil World Cup training|
|FIFA opens disciplinary proceedings over alleged Mexico homophobic chants|
|Cisse hoping to be a pioneer for black and African coaches|
|World Cup over for Croatia´s Kalinic|
|Defiant Jones confident of upturn in England fortunes|
|Pogba a natural leader for France - Matuidi|
|Frampton to face Jackson as Fury continues comeback in Belfast|
|Team effort needed for Japan to stop James, says Nishino|
|Di Francesco extends Roma contract|
|It was a normal challenge - Switzerland equaliser fine by Shaqiri|
|Hamilton hopes to avoid ´boring´ French Grand Prix|
|Coutinho expects more Neymar punishment at World Cup|
|Cisse hails Mane as ´one of the best players in the world´|
|Forsberg falls flat as Granqvist proves Sweden´s hero|
|Sweden 1 South Korea 0: Granqvist´s VAR-assisted penalty settles tight game|
|Nishino concerned Japan players affected by Osaka earthquake|
|Isco pleased with Lopetegui´s Real Madrid appointment|
|Hazard hints at Real Madrid interest|
|Wasps disappointed as Wilson joins Scotland backroom staff|
|Hierro has full confidence in De Gea|
|Russia will stop Salah - Cherchesov|
|Allen signs new four-year Stoke contract|
|England issue update over injured duo Stokes and Woakes|
|Mancini leaves door open for Buffon´s Italy return|
|Alli calls for England to be ruthless in World Cup opener|
|Tahir rested as Proteas call up uncapped duo|
|Uruguay v Saudi Arabia: Centurion Suarez seeks World Cup redemption|
|Portugal v Morocco: Hat-trick hero Ronaldo hunts stricken Atlas Lions|
|Argentina didn´t draw because of Messi´s missed penalty - Maradona|
|Wenger heaps praise on France star Kante|
|If VAR helps referees, I´m not against that – Australia´s Sainsbury|
|Kimmich questions Germany mentality after shock defeat|
|Roberts to leave Warrington Wolves|
|Australia talent Arzani ready to make the jump from A-League|
|Lewandowski: I can be at the top until I´m 35|
|All Blacks winger Savea confirms Toulon switch|
|Free Fall available for France after red card rescinded|
|South Korea can progress from wide-open group, says Park Ji-sung|
|Gordon called up by Wallabies to replace injured Genia|
|Germany can still win World Cup, insists Werner|
|Man United & Real Madrid talk not affecting Milinkovic-Savic|
|Out-of-contract Ruiz focused on Costa Rica|
|Southgate will not bombard England with last-minute instructions|