The inspiration behind Coleen and Wayne’s baby’s name has been revealed

So, that's why they broke with the K tradition.

Coleen Rooney and husband Wayne welcomed their fourth child earlier this week. Coleen confirmed the news through social media that their fourth boy, Cass Mac, was born.

So Happy to welcome our Baby Boy .... Cass Mac Rooney into the world weighing a healthy 8lb 10oz. He is beautiful ?

— Coleen Rooney (@ColeenRoo) February 15, 2018

While everyone is loving the baby's name, they have been left wondering why the couple broke with their baby name tradition of using names beginning with K. They already have three sons together, Kai, Klay and Kit. So, when Cass Mac was introduced to the world it wasn't what everyone expected. But, it turns out he was named after legendary boxer Cassius Clay. Wayne got to decide this name and he originally wanted to go for the full name of Cassius, but a fellow football star had already called his son by that name, so he decided to shorten it. A source told The Sun, "Wayne is a huge boxing fan. He really wanted to call his son Cassius but Joey Barton stole that. So they decided to shorten it to be a bit more original and couldn’t be happier. They’re on cloud nine.”