Rousey made the comment as part of a Q&A session Wednesday on YouTube. Lynch fired back Thursday on Twitter by making reference to WrestleMania 36 opponent Shayna Baszler, who was part of Team Rousey on the UFC's reality show, The Ultimate Fighter, in 2013.
"You better hurry up and beat me, Shayna. Auntie Ronda is casting her shadow again now you've got yourself a little bit of the spotlight," she wrote.
Lynch defeated Rousey and Charlotte Flair in the main event of WrestleMania 35 last year to unify WWE's women's titles.
Rousey hasn't competed in a WWE ring since that match and said in the YouTube video her return date still isn't settled because she's still trying to start a family with husband, former UFC heavyweight Travis Browne. She debuted with the company at WrestleMania 34 and holds the second-longest reign as the Raw women's champion.
The 33-year-old California native initially responded with "no" when asked whether she'd be at WrestleMania 36, but she backtracked to leave open the possibility of an appearance. WWE's biggest show of the year was already taped in order to avoid possible complications of holding it live amid the coronavirus pandemic.
WrestleMania will air on WWE Network and via pay-per-view across two nights Saturday and Sunday.