When Jannik Sinner ended his 2026 season on October 6 with a knee injury, he ruled himself out of the ATP Finals in Turin, the event he had won in each of the previous two years, Reuters and AFP reported. At the time he was second in the ATP’s Live Race To Turin, 800 points behind Alexander Zverev, according to the ATP Tour.
His absence does not leave a hole in the eight-man field. The ATP Rulebook decides who fills it, and the same rules guarantee a spare player on site in case anyone else drops out once the tournament has started. Here is how it works.
How the selection list is built
Qualification for Turin is not decided by a single cut-off number. The rulebook builds an ordered selection list on the Monday after the last ATP Tour tournament of the calendar year: first the top seven players in the ATP Rankings, then up to two Grand Slam champions of that year who are ranked between eighth and 20th, then everyone else from eighth place down.
The top eight names on that list are the direct acceptances. Participation is mandatory for them, and all must be at the site for the official pre-tournament media conference and available through the end of the round robin and the knockout rounds if they advance. During the season the ATP tracks the running count as the Race To Turin; how those points are counted is a separate question from what happens once the list is drawn up. [UNVERIFIED: rule text taken from the ATP’s 2023 Rulebook, chapter 4 (October 2023 edition); the 2026 edition was not checked for changes]
Withdrawal before the tournament
A player who withdraws before the official pre-tournament media conference starts is replaced by the next highest player on the selection list, and that player becomes a direct acceptance in his own right. In practice, a qualifier who is out before the event begins moves the ninth player into the field rather than calling up an alternate.
The alternate
Once the field is set, the next highest player on the list who is not a direct acceptance at the time of the media conference is designated as the alternate. He must attend the media conference and stay available until the start of the last scheduled round-robin match. If a player withdraws after that point, the alternate takes his place. The ATP may also select additional alternates from the list, on terms it agrees with them, and those extra alternates are not obliged to take part.
What an alternate can earn
The rulebook sets out three cases. An alternate who never plays is paid a fee. An alternate inserted for a player’s second or third round-robin match receives that fee plus any prize money and ranking points he wins. An alternate who replaces a player before that player’s first round-robin match becomes a direct acceptance and does not receive the alternate fee. The rulebook does not state the size of the fee.
An alternate is also eligible for the semifinals and final, with the points and prize money that come with them, if he qualifies from the group. That is harder than it sounds. The first tiebreaker in a group is the number of wins, and the second is the number of matches played, so a 2-1 record beats 2-0. An alternate who comes in for the last two group matches and wins both can still be edged out by a player who went 2-1.
Withdrawing during the round robin
A player who withdraws from any round-robin match after the first round is not eligible for the knockout stage. For the group tiebreakers, a retirement or conduct default counts as a straight-set result, but the games from that match are left out of the games-won percentage. A player who retires through illness or injury may continue in the event if the tournament doctor approves.
Not turning up
A direct acceptance or designated alternate who fails or refuses to play, without a bona fide injury or other good cause, is not in good standing with the ATP. Failing to appear at the site and the pre-tournament media conference carries a penalty of five per cent of the player’s total ATP prize money for the year.
The Grand Slam champion clause
The second step of the selection list exists for one scenario: a major champion who has slipped out of the top seven but is still inside the Top 20. In 2026 the majors went to Carlos Alcaraz at the Australian Open, Zverev at Roland Garros and the US Open, and Sinner at Wimbledon, according to AP and Reuters. The clause only changes the field if one of them finishes between eighth and 20th; a champion who is in the top seven takes his place through the first step, and a champion who withdraws is replaced like anyone else. The last ATP Masters 1000 of the year, the Rolex Paris Masters, runs from November 2 to 8.
On the women’s side
The WTA Finals, held at Indian Wells this year, also carries alternates under the WTA’s own rules. Ekaterina Alexandrova played a round-robin match at the 2025 WTA Finals as an alternate and lost to Elena Rybakina, the eventual champion, according to WTA match notes. The women’s qualification rules are covered in our WTA Finals qualification explainer, and both season finales in the ATP Finals and WTA Finals guide.
