Chopra scored five times during his month at Vicarage Road, convincing Lewington that he has a big future ahead of him.
"Next season if Bobby Robson wants to let him out on loan hopefully he will think of us first. I know he's really enjoyed himself here," said the Hornets boss.
"He's had an experience he wouldn't have believed a month ago having played in an FA Cup semi-final. It's early days for him and he needs to learn the game but he will be a good player, no doubt about it."