The 37-year-old, a 22-time Grand Slam champion, said that he is far from being in top form and that he is only playing against American Darwin Blanch in the first round of the Madrid Open on Thursday as a personal sacrifice.
Rafa Nadal's withdrawal from the Monte Carlo Masters has cast doubt over the 22-times Grand Slam champion's participation at the French Open, but Novak Djokovic said he is still hoping for a final chapter in their storied rivalry.
The 36-year-old Serb, champion in Paris in 2016 and 2021, will face 11th seed Karen Khachanov for a place in the semi-finals.
Swiatek blitzed 80th-ranked Wang Xinyu of China 6-0, 6-0 on the back of 21 winners as the 22-year-old Pole took another step closer to becoming the first woman since Justine Henin in 2007 to win back-to-back titles at Roland Garros.
The Belarusian second seed is yet to drop a set in the tournament after a comfortable 6-2, 6-2 win against the world number 82.
Eighth-seeded Sinner, whose best performance at Roland Garros came in 2020 when he lost in the quarter-finals against Rafael Nadal, looked set for a no-nonsense win after cruising through the third set but Altmaier had other ideas.
Following is reaction to Rafa Nadal securing a men's record-extending 22nd Grand Slam title after beating Casper Ruud in Sunday's French Open final:
Rafael Nadal won a record-extending 14th French Open by crushing Norwegian Casper Ruud 6-3 6-3 6-0 on Sunday to claim an all-time best men's singles 22nd Grand Slam title.
Iga Swiatek cruised to her second French Open title by dominating teenager Coco Gauff in the final on Saturday, as the world number one claimed her 35th successive victory.
World number two Daniil Medvedev coasted into the French Open second round Tuesday, beating Argentina's 103rd-ranked Facundo Bagnis 6-2, 6-2, 6-2.
Reigning champion Novak Djokovic won in straight sets on his return to Grand Slam action at the French Open on Monday and 13-time Roland Garros winner Rafael Nadal eased to victory, but Naomi Osaka crashed out in the first round.
French Open favourite Iga Swiatek breezed into the second round at Roland Garros on Monday, beating Ukrainian qualifier Lesia Tsurenko 6-2, 6-0 to extend her winning run to 29 matches.
Teenage Spanish star Carlos Alcaraz said the best part about being touted as the future of Grand Slam tennis was that he is realising a "dream that is not for everyone".
Arab trailblazer Ons Jabeur crashed out of the French Open at the first hurdle on Sunday as Spanish teenage sensation Carlos Alcaraz prepared to give Roland Garros a glimpse of the future of Grand Slam tennis.
Novak Djokovic may not seem like the intimidating tennis virtuoso athlete from the outset; rather, like somebody one might approach in a room full of strangers to ask for the Wi-Fi password, for instance. Fondly referred to as the Djoker, his demeanour in general, feels so vibrant and likeable that one might feel like cracking an informal joke with him; and he seems humble and humane- way more than an average superstar athlete or a comic superhero, yet he has morphed into a champion hero for the ages and for all ages.
No matter the result, tonight's Roland-Garros semi-final promises brilliant tennis.
Andy Murray pays an emotional on-court tribute to the victims of the recent terror attacks in London and Manchester that left 29 people dead and scores injured.
Nine-time champion Rafael Nadal surges into the French Open quarterfinals for a record-equalling 11th time.
Rafael Nadal takes another step closer to a 10th French Open with a ruthless 6-0, 6-1, 6-0 demolition of Georgia's Nikoloz Basilashvili.