Beckham looks set to join AC Milan on a short-term loan deal in January.
“Beckham is a real gentleman and he is also a bit shy,” Flamini told Sky Sport 24.
“He is a very hard worker and it’s great for Milan to have someone like him in the squad.
“I’m really happy that he is coming and so are the other players here. I trained with him for three months and he is a great person on and off the pitch.”