While she was No. 1 when she left the tour to give birth, Williams is now ranked No. 453.
The American is expected to play at Roland Garros next week, where she has won the title three times, but without being seeded she could conceivably meet reigning champion Jelena Ostapenko in the first round.
"Historically, WTA players have not been supportive of the use of special rankings for seeding purposes", the tour said in a statement to the Associated Press, adding, "We remain committed to evolving with the needs of our players and are very supportive of those players returning from maternity leave to the tour".
"It's normal to give birth". It's normal to have protected ranking.
The Tennis star also claimed on Twitter that she still gets tested twice a week for drugs and anti-doping.
According to fourth-ranked Elina Svitolina, Williams is still number one, so she deserves seeding.
Trump tells Navy grads ‘you don’t give up’
A growing number used their platforms to. weaken America's pride". "We are going to be stronger than ever before", he said. On Twitter Friday, Trump said he looks "forward to being with some of the greatest people on earth!" No more apologies.
Serena Williams will be unseeded at the French Open.
"If a woman takes 12 months maternity leave in a workplace, the law allows her to return to the same position", she said.
However, being seeded gives a player a number of advantages.
Williams has played in tournaments at Indian Wells and Miami since taking maternity leave.
Following a tumultuous birth, when she needed emergency surgery after suffering a blood clot, just being back on the court is a remarkable achievement.
"We know she will have the fire, the fight and the heart and the drive but you don't know about seven matches in a row to keep that level up". She may not like it, but she will go with it and prove what she wants to prove in the process. Williams was eventually able to make a recovery, but not before spending her fist six weeks of motherhood confined to a bed in her home.
The French Open draw will be announced on Thursday, and play will begin on Sunday.
"I don't really think so", said Kvitova who was off the tour for six months a year ago after suffering knife wounds fighting off a burglar at her home in the Czech Republic.
"Proud to participate to keep the sport clean", she said.