Tennis star Naomi Osaka — the highest-paid female athlete this past year — is blasting the NFL … taking aim at Roger Goodell and demanding Colin Kaepernick get his job back.

The 22-year-old broke it all down in an email to Reuters this week … saying how she couldn’t believe it took THIS much for The Shield to finally admit it bungled its handling of kneeling protests.

“Colin has been putting this message out since 2016,” Osaka said. “It took a pandemic, an economic crisis and a torturous murder on camera, all at the same time, for people to really hear him.”

“It shouldn’t have been that way. If the NFL wants to show that they really care the first thing they should do is take a knee together and give Colin his job back.”

As we previously reported … Al Sharpton relayed a similar message at George Floyd’s funeral earlier this week, saying if the NFL truly is sorry, it needs to give Colin his job back ASAP.

“We don’t want an apology,” Sharpton said. “We want him repaired!”

As for Osaka, she’s held no punches when it comes to her outspoken role in the fight for social justice … and even in the face of hundreds of trolls online, Osaka says she ain’t stoppin’ anytime soon.

“I’m vocal because I believe in the movement and want to try to use my platform to facilitate change,” Osaka said.

“That some people have said we as athletes should stick to sports is really insulting.”