Rafael Nadal is known for showing the same kind of intensity in his practice sessions as he does in his matches. And right now the World No. 3 is cranking up the volume while training at the Rafa Nadal Academy in Mallorca, as he prepares for an assault on a 21st Grand Slam singles title at the US Open next month.In a recent video posted by his academy, Nadal was seen trading blows with his fellow countryman Alejandro Davidoch Fokina. The two engaged in a fast-paced rally which ended with a diving get by Davidovich Fokina that was subsequently put away by Nadal at the net.Y voló 🌪H🔥t sh🎾t@alexdavidovich1 & @RafaelNadal pic.twitter.com/qJm3qlLUoF— Rafa Nadal Academy by Movistar (@rnadalacademy) July 13, 2021The academy handle posted a couple of other videos too, which showed Rafael Nadal playing out slightly less intense rallies.Welcome back to the #RafaNadalAcademy @alexdavidovich1 👋🏼👋🏼No better way to start off the week than seeing @RafaelNadal and @alexdavidovich1 practicing ‼️ pic.twitter.com/KH8FAtflKz— Rafa Nadal Academy by Movistar (@rnadalacademy) July 12, 2021VAMOOOOS ✨@RafaelNadal & @alexdavidovich1 💥 pic.twitter.com/lhhdTVEpVc— Rafa Nadal Academy by Movistar (@rnadalacademy) July 13, 2021Nadal has not played on the tour since losing in the semifinals of the French Open last month to Novak Djokovic. The Serb went on to win the final at Roland Garros for his 19th Major, and followed that up by lifting a record-tying 20th Grand Slam trophy at Wimbledon last week.Nadal pulled out of Wimbledon citing exhaustion from a grueling claycourt season. He has also withdrawn from the Tokyo Olympic Games later this month.Davidovich Fokina, meanwhile, reached the quarterfinals of the French Open last month. However, he was subsequently knocked out in the first round at Wimbledon.Welcome back @alexdavidovich1 ! 👋🏼We hadn't seen you in 2 years! In 2018 he became the champion of the U23 Spanish National Championship, in August of 2019 he came to Manacor to play at the @ATPChallenger and now, two years later he is back training with @RafaelNadalVAMOS! 🔥 pic.twitter.com/HRustm27jx— Rafa Nadal Academy by Movistar (@rnadalacademy) July 13, 2021Rafael Nadal to return to the circuit in WashingtonRafael Nadal is scheduled to make his return to the ATP tour next month at the Washington Open, an ATP 500 series event. It remains to be seen if Nadal will play the Masters 1000 events at Cincinnati and Toronto, which will be followed by the US Open.The final Grand Slam of the season kicks off on 30 August in New York City. It is worth noting that the last time Nadal played the US Open - in the year 2019 - he walked away with the title.Rafael Nadal at the 2019 US OpenWith Novak Djokovic winning a sixth Wimbledon singles title and tying Roger Federer and Rafael Nadal at 20 Slams (the most in the history of men's tennis), the race for No. 21 has heated up. Federer is unlikely to add to his tally this year, given that he recently pulled out of the Tokyo Olympics due to a new setback with his knee. But for Nadal and Djokovic, there is a lot to play for in New York next month.