The pair played together with Barcelona B.
"Kiko, before is a good player, but now it's an amazing player," Deulofeu said.
"He plays so well for Watford and I'm happy to be with him. I want to be a good partner with him if I play on the right side."
"I think when you take years and when your age is more, you have confidence," Deulofeu explained, "you have experience and you play well."
Watford had hoped Chalobah would return to training in December, after having surgery on the injury shortly after it occurred.