Miesha Tate is questioning Ronda Rousey's focus -- saying Ronda's more worried about having babies than fighting ... and it's going to hurt her when they step in the Octogon.
Tate joined the guys on "TMZ Sports" (airs tonight on FS1) -- when we asked her how she felt about fighting Rousey for a 3rd time.
Tate says she's 100% down -- but says she's not sure the feeling is mutual.
"I don't even know what [Ronda] is thinking right now ... it seems like her motivation to stick around was to have Travis Browne's baby.