Seven months after his last match, Nick Kyrgios will step onto the court in Stuttgart, aiming to get time on the grass in readiness for next month's return to Wimbledon.
Kyrgios faces China's Wu Yibing on Tuesday in Germany (early Wednesday AEST) in the opening round of a tournament in which he lines up as eighth seed.
The 28-year-old last played on tour in the ATP Finals doubles tournament alongside Thanasi Kokkinakis in November, but has not played singles since October.
He was forced out of the Australian Open by the need for surgery on a meniscus tear on his left knee following a big-money exhibition appearance in Saudi Arabia in December.
“I wouldn’t say it was major surgery, but I had quite a serious surgery on my knee” said Kyrgios ahead of his return.
"It's taken me about five months to get back to even playing, moving and (ready to play) against these players.
“It’s been difficult, but at times it’s been amazing just to be home with my family.
"Tennis is a sport where you travel so much of the year and being home, for me, was important.
"But seeing everyone (else) play wasn’t easy, at times.
"I’m just super excited that my knee is a bit better and I’m able to play now.”
The world No.25 had a memorable run to the final of Wimbledon in 2022 and needs to gain match-sharpness for this year's tournament.
A two-time Stuttgart semi-finalist Kyrgios added: “The grass season for me is always the best part of the year.
"This year has been really tough for me, obviously recovering from knee surgery.
"I’m coming back at a tournament (where) I’ve done really well in the past, played some amazing matches.
"I’m super excited to be here again and to get out there and play.”
Kyrgios's predecessor as Wimbledon runner-up, Matteo Berrettini, is the holder in Stuttgart but his defence is already over.
The world No.21 was beaten 6-1 6-2 by fellow Italian Lorenzo Sonego.
Berrettini, who is also coming back from injury, lost in 71 minutes to the 41st-ranked Sonego.
“Today I played my best tennis. This is my first tournament on grass, my first match, and I played really well. I’m really happy about that,” said Sonego, who added that Berrettini is his “best friend on tour and it’s tough to see him like that. I hope the best for him in the next tournament.”
Jiri Lehecka, Richard Gasquet and Lorenzo Musetti progressed with wins over Marcos Giron, Christoper Eubanks, Borna Gojo respectively while Spanish veteran Feliciano Lopez went down to Yosuke Watanuki.
Also playing on Tuesday is the other Australian in the tournament, Chris O'Connell, against Germany's Daniel Altmaier. Top seeds Stefanos Tsitsipas and Taylor Fritz have first-round byes.
In another ATP 250 tournament, at 's-Hertogenbosch in the Netherlands, Jason Kubler went out 6-4 6-2 to Ugo Humbert. Alexei Popyrin and Jordan Thompson play Tuesday.
Rinky Hijikata is also in the first round draw while Alex de Minaur has a bye to the second round.
