The tennis world was stunned by Felix Auger-Aliassime’s shock defeat to Fabio Fognini in the first round of the 2023 French Open on Monday. The World No. 10 was ousted in straight sets by the 130th-ranked Italian 6-4, 6-4, 6-3.The Canadian became the first top 10 player to exit this year’s clay court Grand Slam in the men's singles, and later admitted to being sick the previous night in his post-match conference. Auger-Aliassime also took a bathroom break and a medical time-out during the first two sets.Last year, Felix-Auger Aliassime had a stellar run in Paris, taking 14-time French Open champion Rafael Nadal to five sets before falling in the quarterfinals. Fans expressed their disbelief at the stark contrast from that performance as he went down easily in the 2023 edition.Tennis analyst Jose Morgado stated this season has been a “nightmare” for the Canadian.“#10 Felix Auger-Aliassime is the first top 10 player to lose in the #RolandGarros men's singles draw. 6-4, 6-4, 6-3 for Fabio Fognini, who can be and was very good. Felix, though, clearly struggled to move. It's been a nightmare season…” he wrote.José Morgado@josemorgado#10 Felix Auger-Aliassime is the first top 10 player to lose in the #RolandGarros men's singles draw.6-4, 6-4, 6-3 for Fabio Fognini, who can be and was very good.Felix, though, clearly struggled to move. It's been a nightmare season...82445#10 Felix Auger-Aliassime is the first top 10 player to lose in the #RolandGarros men's singles draw.6-4, 6-4, 6-3 for Fabio Fognini, who can be and was very good.Felix, though, clearly struggled to move. It's been a nightmare season...Another user expressed that tennis was “crazy” as a player who took Nadal to five sets crashed out in the first round.“Auger Aliassime. From the best challenge Nadal had at last years FO to eliminated in R1 to Fognini. Tennis is crazy,” they wrote.Tennis World (Mike)@secondservesAuger Aliassime From the best challenge Nadal had at last years FO to eliminated in R1 to Fognini Tennis is crazy3Auger Aliassime From the best challenge Nadal had at last years FO to eliminated in R1 to Fognini Tennis is crazyazazel_2100@2100Azazel@josemorgado How do you go from pushing Nadal to 5 sets to this?9@josemorgado How do you go from pushing Nadal to 5 sets to this?Others acknowledged that Felix Auger-Aliassime did not look fit enough to continue playing and thought he should have retired.The Tennis Podcast@TennisPodcastFabio Fognini d. Felix Auger-Aliassime 6-4, 6-4, 6-3.Obviously FAA was not really fit to be playing. But that's also Fognini's first win over a top-10 player at the French Open in six attempts - and his first at a Grand Slam since beating Rafael Nadal at the 2015 USO.27Fabio Fognini d. Felix Auger-Aliassime 6-4, 6-4, 6-3.Obviously FAA was not really fit to be playing. But that's also Fognini's first win over a top-10 player at the French Open in six attempts - and his first at a Grand Slam since beating Rafael Nadal at the 2015 USO.jdot@Jbekillin_Felix Auger-Aliassime just retire man wtf u waiting for12Felix Auger-Aliassime just retire man wtf u waiting forJoão Pinto 🎾@joaopintoatpAuger-Aliassime is the first top 10 to fall in #RolandGarros this year.Fognini takes the match. 6-3 6-3 6-4Poor Felix, struggling with some injuries so far in this season...271Auger-Aliassime is the first top 10 to fall in #RolandGarros this year.Fognini takes the match. 6-3 6-3 6-4Poor Felix, struggling with some injuries so far in this season... https://t.co/UhlppeIfh0Gaspar Ribeiro Lança@gasparlancaFabio Fognini gets the win in three sets: 6-4, 6-4, 6-3 against World No. 10 Félix Auger-Aliassime. I didn’t get to see much of this but it sure didn’t look like Fognini was facing a top 10 opponent. Tough two weeks for FAA with the shoulder injury…61Fabio Fognini gets the win in three sets: 6-4, 6-4, 6-3 against World No. 10 Félix Auger-Aliassime. I didn’t get to see much of this but it sure didn’t look like Fognini was facing a top 10 opponent. Tough two weeks for FAA with the shoulder injury… https://t.co/q8B44XdAMHDennis Gavin@TheDennisGavinGiven Felix’s form I’m not that surprised… what a Loud win for the veteran FF. Hopefully Felix can regain his top 10 player form on Grass/Hard Court twitter.com/josemorgado/st…José Morgado@josemorgado#10 Felix Auger-Aliassime is the first top 10 player to lose in the #RolandGarros men's singles draw.6-4, 6-4, 6-3 for Fabio Fognini, who can be and was very good.Felix, though, clearly struggled to move. It's been a nightmare season...82645#10 Felix Auger-Aliassime is the first top 10 player to lose in the #RolandGarros men's singles draw.6-4, 6-4, 6-3 for Fabio Fognini, who can be and was very good.Felix, though, clearly struggled to move. It's been a nightmare season...Given Felix’s form I’m not that surprised… what a Loud win for the veteran FF. Hopefully Felix can regain his top 10 player form on Grass/Hard Court twitter.com/josemorgado/st…Mathias Malmgren@matmalmgren@josemorgado FAA looked depressed out there. Clearly not fit for fight. Surely something he knew in advance. Would have been a nice gesture to leave his spot to a happy LL who most likely needs the price money better than he does.5@josemorgado FAA looked depressed out there. Clearly not fit for fight. Surely something he knew in advance. Would have been a nice gesture to leave his spot to a happy LL who most likely needs the price money better than he does.Clint.@CleanThing_Struggled to move but didn’t retire in the first/second set. Clown twitter.com/josemorgado/st…José Morgado@josemorgado#10 Felix Auger-Aliassime is the first top 10 player to lose in the #RolandGarros men's singles draw.6-4, 6-4, 6-3 for Fabio Fognini, who can be and was very good.Felix, though, clearly struggled to move. It's been a nightmare season...945#10 Felix Auger-Aliassime is the first top 10 player to lose in the #RolandGarros men's singles draw.6-4, 6-4, 6-3 for Fabio Fognini, who can be and was very good.Felix, though, clearly struggled to move. It's been a nightmare season...Struggled to move but didn’t retire in the first/second set. Clown twitter.com/josemorgado/st…“Yeah, sick all night” - Felix Auger-Aliassime reveals the reason for his shock defeatFelix Auger-Aliassime reveals illnessSpeaking in the post-match press conference, Felix Auger-Aliassime revealed he was sick all night and did not get sleep leading up to his first-round clash with Italian Fabio Fognini.He also added that his shoulder was still not in great shape.“Yeah. I mean, the shoulder is not great, but that wasn't the issue today. I got a bit sick last night, didn't really sleep. Yeah, sick all night,” said the World No. 10.The 22-year-old admitted he could not move and was experiencing cramps after the first set.“I tried to see the doctor, see what I could take, but after one set, you know, just cramping and just can't move anymore,” he added.With a win-loss record of 13-9, the Canadian has had a tough season so far. He will hope to get healthy and come back for the grass swing next month.