Garbiñe Muguruza salutes “pioneer, trailblazer” Serena Williams in El País editorial

WATCH: Serena reached the third round in what will likely be her final US Open appearance last week.

In an editorial for El País, Garbiñe Muguruza reveals that as the tennis world collectively mourns Serena Williams’ “evolution” away from tennis, few have taken the news harder than the former world No. 1 herself.

“I cried when she told us she was retiring, which is very rare for me,” Muguruza wrote. “Somehow, her goodbye has shut down something inside me; something was extinguished. When she announced that it was time to evolve and take the next step, which is only logical and perfectly fine, I thought: ‘No, Serena’s leaving! Now what? Now who’s going to be the one to really lead tennis, to be an unmatched role model that we can look up to? Who will take on the legend’s mantle?’ That’s how much she means to me.”

When she burst onto the scene, she created a “before and after” that forced us to be better. All of us, including me, have studied her game in depth...That’s the only way to face the tennis player who has blazed a new trail. Garbiñe Muguruza on Serena Williams

Muguruza famously defeated the 23-time Grand Slam champion to win her first major at the 2016 French Open; a year earlier, she finished runner-up when Williams completed her second Non-Calendar Year “Serena” Slam at the 2015 Wimbledon Championships.

But Muguruza has memories of Williams that go beyond their time competing for major trophies, recalling how she sought to emulate Serena and sister Venus from her earliest hours on the tennis court.

“Many of us have identified with her, either because of her story or because of the message she has conveyed, which always went beyond the court,” she wrote. “Her heart is what has really influenced me. It has often made me train harder and motivated me to keep going.”

In assessing her legacy and addressing the ongoing GOAT debate, Muguruza believes Williams’ ascendency is indisputable.

“Serena took the game by storm and turned it into another type of sport, one that’s more aggressive, stronger, faster and more explosive. From that point on, players all had to adapt if they wanted to compete at her level, or at least close to it. For all these reasons, she’s the greatest of all time. There’s no doubt about it.”

Click here to read the full editorial, which includes insight into Muguruza’s first match against Serena at the 2013 Australian Open and where she feels the game goes from here.