The partnership nobody planned but everyone will watch is now official. Serena Williams and Carlos Alcaraz have been handed a wildcard into the US Open mixed doubles, set to run from 24 to 26 August — four days before the singles draw even begins. Between them they hold 44 Grand Slam titles in singles and doubles combined, a number that dwarfs most players' career ambitions. It is the kind of pairing that makes a revamped format suddenly feel very relevant.

Both players are carrying more than just rackets. Williams, a 23-time Grand Slam singles champion, made her return to the sport in June after a four-year absence. Since then she has played three doubles matches, lost alongside Venus at the Cincinnati Open after injuring her knee at Wimbledon, and missed out on a singles wildcard in New York to Sofia Kenin. Alcaraz, a seven-time major winner, has not played competitively for over four months due to a wrist injury.

For both of them, Flushing Meadows is a genuine comeback stage. They will not be short of company in the star-studded draw. World number one Aryna Sabalenka partners Novak Djokovic, who has 24 major titles of his own. Iga Swiatek teams up with Casper Ruud, while Jessica Pegula and Taylor Fritz represent the home crowd.