Former World No.1 Ana Ivanovic announced the latest addition to her growing family on Friday morning.
The 2008 Roland Garros champion, who retired at the end of the 2016, tweeted, "Our boy got a little brother," indicating the birth of her second child with husband Bastian Schweinsteiger.
Ivanovic married Schweinsteiger in the summer of 2016, and gave birth to her first child last spring - also a boy, named Stefan.
A professional soccer player, Schweinsteiger also shared the news on his social media, declaring, "Our heart are fulfilled with a new arrival in our family."
Ivanovic reached three major finals - two at Roland Garros - and became World No.1 after winning her maiden major title in Paris back in 2008.
She reached the quarterfinals or better of all four major tournaments, including the US Open back - which will crown its latest champion next Sunday - in 2012.
The 31-year-old Serbian star is currently based in Chicago, where Schweinsteiger plays for the Chicago Fire.