Double Olympic gold medallist Zou Shiming has some bad amateur habits, says Freddie Roach.

Zou admits he has a lot to learn ahead of his professional debut next month but the Chinese flyweight enjoyed the best possible education from hall of fame trainer Roach on Wednesday.

Zou has prepared for the bout in the United States and on Wednesday was put through his paces at Roach's famed Wild Card Boxing Club in Hollywood. He sparred with WBA and WBO flyweight champion Brian Viloria.

Zou's amateur success was built on hand speed, elusiveness and his ability to throw punches from all angles. But that style could come unstuck against heavy-punching professionals.

Roach, who has worked with some of boxing’s greats, including multiple world champions Bernard Hopkins and Manny Pacquiao, believes the 31-year-old Zou has room for improvement.

"For him to come into this venue, with Brian Viloria being his number one sparring partner and flyweight champion of the world and probably someone who he may be after some day … it's great for him and he has learned a lot," Roach said.

"He has a lot of potential but he still makes a lot of amateur mistakes. He has a lot of bad habits, but we are getting rid of them slowly. He's becoming a very good fighter," the American explained.

Zou agreed he had a lot of adapting to do, but was looking forward to headlining a card that also features Viloria defending his titles against Mexican Juan Francisco Estrada.

"I'm pretty good and I think I am ready for the first fight," Zou said. "From the start I'm learning what to do inside the professional ring. But, now I am getting comfortable with the rules here and I feel ready."

After demonstrating ferocious accuracy and a mean left hook as he pounded the gloves of Roach during the session, Zou said he was also concerned about improving his fitness.

"As an amateur we do all of our boxing in three rounds. As a professional, you have 12 rounds to show what you can do. This is a big challenge for my physical condition. I am working on this.

"The skills for amateur boxing and professional boxing are the same and I think that I have those."