Even before injury scattered the men’s draw like so much chaff to the wind, discussions about who would win the US Open had already settled on the familiar shoulders of Rafael Nadal and Roger Federer, who have eight American titles between them.

However, when Andy Murray withdrew injured after the draw had been made, minor chaos and controversy ensued. Because of rules governing the grand slam tournaments, Marin Cilic, the 2014 champion and a Wimbledon finalist this summer, moved from fifth seed to take the Scot’s No2 place against the American Tennys Sandgren.

Sam Querrey, who beat Murray at Wimbledon and has been in the form of his life this year, took Cilic’s spot against Gilles Simon, and they play on Tuesday. That allowed Philipp Kohlschreiber to occupy Querrey’s place and he has what should be a gentle workout against Tim Smyczek. Completing the jigsaw, Lukas Lacko, the luckiest of lucky losers, was added to the field.

However, that threw up the argument that Federer, the second seed and owner of two slam titles in this glorious comeback season, has been hard done by in many people’s estimation. The Australian coach and TV commentator Darren Cahill agreed with the suggestion that the Swiss should have been moved to second seed, which would have kept him away from the world No1 Nadal until the final. “But that makes too much sense,” he said.

Nevertheless, however crazy the rule might seem it would be equally daft and unfair to change it after the draw had been made. So that means the two best players in the tournament – and in the game, again, after a few years watching Murray and Novak Djokovic occupy their elevated positions – are slated to have their first US Open confrontation in this year’s semi-finals.

Federer, who has won it six times, begins his campaign on Tuesday against the young American Frances Tiafoe while the two-times champion Nadal plays the Serb Dusan Lajovic.

All other considerations are diminished by this prospect. Certainly it would be uplifting if one of the new contenders crashed the party, and the most likely of those is Alexander Zverev, whose rising stature earned him the second night match on the main court on day one, against the Bajan Darian King.

On the other side of the draw more sharks lurk. The rejuvenated Grigor Dimitrov, a winner in Cincinnati last week, awaits Nadal in his quarter, and Federer’s most likely stumbling block before the semi-finals is the unpredictable Nick Kyrgios.