The Blues recently completed the signing of Rahman from FC Augsburg and the Ghanaian international could prove to be a great addition for the reigning English champions.
Rahman will now don the 21 number jersey at Stamford Bridge with the name Baba on his back and the defender has revealed the reason behind him using Baba instead of Rahman.
The Ghanaian star told the official Chelsea website: "It's because my dad's name is Baba, I love my dad so that's the reason.
"He's a Chelsea supporter so he's very happy and proud. He's not in the country at the moment but he will definitely be watching every game."