The 13-time Roland Garros champion posted a picture of himself training in full flow at his academy in Mallorca with the caption: "See you on Wednesday, Paris."
Ostapenko outplayed Veronika Kudermetova of Russia 6-0, 6-4 for her fifth career crown.
A member of the French Parliament, Christophe Castaner, said that the new law will apply anyone who wants to play in the French Open a reversal of earlier plans to create a bubble around the tournament.
The former world No. 1 becomed the first woman to lead the Roland Garros tournament.
Sindhu squandered a one-game advantage to lose 21-18, 16-21, 12-21 to the world No. 15 Takahashi.
Sameer Verma retired hurt against Indonesia's Shesar Hiren Rhustavito at the end of the second game.
The Indian shuttler beat Korea's Lee Dong Keun in straight games.
The recurring issue flared up at the French Open, where he fell to eventual champion Novak Djokovic in the semi-finals.
She was one of just 10 women in tennis history to have won singles titles at all four Grand Slams.
The Serbian world No. 1 increased his Grand Slam tally to 19 titles, and is now one adrift of the men's record held by Roger Federer and Rafael Nadal.