Becky Lynch's Advice To Ronda Rousey After Giving Birth, Don't Come Back!!

Becky Lynch has some heartfelt advice for Ronda Rousey -- IF the WWE Superstar wants to return to the wrestling ring after giving birth to a beautiful baby girl ... DON'T!!

Of course, The Man and Rowdy Ronda have major beef ... but they also have something in common -- they are new moms.

Lynch -- who relinquished her title when she went on maternity leave -- gave birth to a baby girl in December with hubby Seth Rollins. She recently returned to the ring ... and is already SmackDown champ.

TMZ Sports talked to Becky and we asked her if she had any advice for Rousey, who also gave birth to a baby girl with husband Travis Browne in late September ... and she did, sorta.

"Don't [come back], cause I'm still on top, Ronda, you won't like it. That's my advice."

We also asked Lynch -- who has a huge match scheduled against Sasha Banks Friday night on a special 2.5 hour SmackDown on FS1 -- about her return to the squared circle ... following the baby.

"It's been crazy, Mike. It went from zero to 100 real quick. Coming back, and coming back on top after not wrestling for a year and a half. It's been wild, but it's been amazing. And, my baby comes along everywhere with me."