Zamora made his senior international debut in the friendly against Hungary last month, but a thigh injury ruled him out of contention for the opening Euro 2012 qualifier with Bulgaria tomorrow.
The much-travelled 29-year-old has netted three goals in his four appearances with Fulham this season.
Hughes - who took over at Craven Cottage following Roy Hodgson's departure for Liverpool - believes there is more to come.
"When you come into a new situation you are not quite sure what you are getting, but Bobby is a top class Premier League striker," Hughes told the club's website. "His link-up play has impressed me and is better than people give him credit for.
"Bobby is quite a package and a threat. His link-up play and team work is excellent and he is a big factor in why we have started so brightly.
"He is very confident in his game and he is enjoying his work.
"At the moment he is able to transfer the work on the training ground on to the field of play and is playing really, really well."