The 27-year old, who is the first American to sign with the Italian giants, believes the experience will only make him better.
"We have a long time before the season starts. This preparation will only help me and the team get better. I feel good, my teammates make me feel comfortable, and I am happy to be on the field,'' Onyewu said.
"I don't ever grade myself publicly, but I think we fought well and fought hard and we didn't capitalize on some chances. But the fact we created a lot of chances will be good in the long run."