The 2025 Monte-Carlo Masters is the only non-mandatory Masters 1000 tournament on the ATP schedule. Three players have chosen not to play, although Jannik Sinner could not feature even if he wanted to.
Carlos Alcaraz and Novak Djokovic are among the top players on the entry list for the 2025 Monte-Carlo Masters. Although it is not mandatory, close to all of the eligible players for the main draw plan to compete at the tournament.
Sinner cannot play in Monte-Carlo until May 4th because of his suspension from ATP events. He has officially been banned since February 9th after settling his high-profile doping case with the World Anti-Doping Agency (WADA).
The two-time Australian Open champion was scheduled to appear at the Court of Arbitration for Sport in April after WADA appealed the International Tennis Integrity Agency's decision to clear him, but ultimately, the case was settled.
However, Sinner almost certainly planned to skip the Monte-Carlo Masters anyway, based on his coach Darren Cahill's comments and the schedule they had been developing before his case settlement was announced.
Cahill previously said that the one week between the Miami Open and the Monte-Carlo Masters was too quick a turnaround, and Sinner would focus on taking a longer break and getting more practice time on clay before playing his opening tournament on the dirt.
Sinner had also been announced for the 2025 Munich Open, which starts on April 14th, the day after the Monte-Carlo Masters ends. His suspension was a body blow for the tournament organizers after advertising the 23-year-old's involvement.
While Cahill did not officially confirm that Sinner would skip the event in Monte-Carlo, the Australian's remarks about the turnaround time and his player signing up for the Munich Open strongly indicate that he would have missed the tournament.
The ATP world No. 1 will also miss the 2025 Madrid Open, but his ban ends before the start of the 2025 Italian Open. Returning on home soil might be a relief for Sinner since he is guaranteed to receive great support from the crowd.
Tommy Paul is one of two American players not on the Monte-Carlo Masters entry list. His most recent match was a comprehensive round-of-16 defeat to Daniil Medvedev at the ongoing 2025 Indian Wells Open.
Paul has made superb progress in the last couple of years, but clay is his weakest surface. None of the 27-year-old's seven ATP finals have been on the dirt, and he has never advanced past the third round of the French Open.
Alex Michelsen is the other American not on the Monte-Carlo Masters entry list. Like Paul, the talented 20-year-old's worst surface is clay since it is harder for him to hit winners with his powerful game, and he also does not move comfortably on it.
Paul and Michelsen might feel they need some additional time to practice on clay before playing tournaments since they are not naturals on it, or it could indicate they are not targeting the clay court season as much as other players.