It's Isaiah Hartenstein's wife's turn for the spotlight ... the NBA champ's spouse tells TMZ Sports she's going to be a featured ring girl at Friday night's Katie Taylor vs. Amanda Serrano bout!!
Kourtney Hartenstein, of course, used to be a regular at big fights -- strutting her stuff in between the ropes during boxing breaks -- but when she got pregnant with her and Isaiah's child last year, her card-holding duties took a back seat.
Launch Gallery Launch Gallery Kourtney, though, told us this week she's ready to make her return when Taylor and Serrano throw down later in New York City .