Blake said that the WTA has treated Williams harshly ahead of her opener with Osaka today.
The Japanese player, up to world No 22 after her maiden title victory at the BNP Paribas Open in Indian Wells, won 6-3 6-2 against the returning American great at Crandon Park.
Tennis superstar Serena Williams picked up a shovel for today's ground breaking ceremony at Hard Rock Stadium, which will soon serve as the new home for the Miami Open tennis tournament.
"She'll probably be the first person to win a tennis tournament she owns", Dolphins majority owner Stephen Ross said with a laugh.
James Blake, Miami Open tournament director, said afterwards that: "It makes sense to protect someone who goes on maternity leave".
She didn't drop a single set at Indian Wells and defeated top-ranked Simona Halep, five-time major victor Maria Sharapova, and Grand Slam finalists Agnieszka Radwanska and Karolina Pliskova.
Now players who hold a protected ranking for any reason - on both the men's and women's tours - can't be seeded even if their protected ranking merits it and Blake told AFP: "For someone who goes on maternity break, they should be protected".
Osaka underlined why she is being tipped as a future Grand Slam champion with some clean ball striking from the back of the court and accurate serving to comfortably close out the match in the second set and bring up a second-round meeting with fourth seed Elina Svitolina.
"It's not as if she left because of injury and lost her passion for the game".
Williams has never needed an extra boost by the game's authority or schedulers to become an all-time great - nor does the fact she's unseeded mean she won't go deep or even win in Miami such is her stature - but the point is a bigger one than that.
"I actually started playing pain-free in the last two days". She, however, has a risky first-round opponent in Japan's Naomi Osaka, who emerged as the surprise victor at Indian Wells. "Women should not be penalized for giving birth by starting from zero".
The former world number one has been beset with an elbow injury that sidelined him for six months after he was forced to retire at the quarter-finals of Wimbledon previous year.
In her comeback in Indian Wells, she made it through to round three where she fell to sister Venus in straight sets. Also, on the other half of the draw, Victoria Azarenka, who like Serena Williams is also a high-profile mother on the WTA Tour, faces promising young American player Cici Bellis in another fascinating first-round match-up. Having a part-ownership of the tournament is something that I will look forward to.
"I was extremely nervous coming onto the court", Osaka said.