Gaffes

Because the "modern day" tennis match took much longer to film than originally scheduled (15 days rather than 5), the number of extras available decreased as time went on. But since the director decided early on to save time between shots by not having the extras change outfits when they were repositioned, you can see people in the crowd appearing to be at once on opposite sides and on opposite ends of the court within individual scenes.

(at around 1h 33m) The "Road to the US Open" promo poster in the hallway shows Donaldson swinging the racquet left-handed, when in fact he plays right-handed.

Right after the make-out scene, when Zendaya gets up to leave, in one shot her hair is behind her back and in the next her hair is in front without moving it.

After Patrick loses the second set in his final round match against Art and smashes his racket, the chair umpire declares a code violation point penalty; however, it should have been a game penalty, as Patrick had already received a point penalty earlier in the match (the scoreboard at the bottom accurately reflects the correct score).

In the last set at 5:5 the scoreboard shows that Zweig is serving, while in fact Donaldson is. The same mistake happens at 6:5 when Donaldson is marked on scoreboard as the server, while Zweig is serving to stay in the match.

Throughout the film, chair umpires would announce the names of the players before before the match as they are setting down their equipment on the sidelines; however, announcements of player names and where they are from are always made during the warm-up or right before walking on court.

During the rally where Art and Patrick are both at net, Art smashes the ball and then touches the net and his opponent, which are both illegal according to the rules of tennis while the ball is still in play.

When Tashi suffers an accident on court it is her right knee which is damaged. Near the beginning of the film when Art is lying in bed and she goes to get ready in the bathroom, it would appear that the scar is on her left knee. However, this is a shot of a mirror, as made evident by the watch on her right wrist appearing to be upside down and also clearly being worn on her left wrist in subsequent scenes.

The large poster on the building of Tashi Duncan and Art Donaldson is an advertisement for the Aston Martin DBX707, a performance SUV which released in 2022. This shouldn't be possible as the scenes take place in 2019.

Near the end, Art says, "I don't want to be one of those guys who doesn't know when to walk away", rather than the grammatically correct "don't know" (defining those guys as a group).