The Phoenix Mercury star dropped the exciting news on CBS Sports' "We Need To Talk" ... prior to the WNBA's All-Star Skills Challenge and 3-Point contest in Phoenix, Arizona.

"He's here," the Phoenix Mercury center said. "Seven pounds, eight ounces."

The WNBA champ and Cherelle -- who she married in 2019 -- haven't shared any photos of their newborn on social media just yet ... but Griner said she's thrilled to be a "pops."

"He is amazing!" she added. "They say you know as soon as you see him, everything that you thought mattered just goes out the window and that's what literally happened."

"Kinda sucks because I gotta leave, but at the same time ... he'll understand."

Of course, Griner is referring to the Summer Olympics in Paris ... as Team USA will start off its quest for a gold medal with a showcase against Germany next week.

But, the 6-foot-9 center will get as many updates as possible ... 'cause she says she expects to receive a ton of pictures while she's out in France.

"My whole phone is turned into him now," Griner said.

We actually spoke with Griner last month about her bundle of joy ... and she told us she can't wait for him to start playing sports -- just like her!