Juan hopes AS Roma teammates Daniele De Rossi and Mirko Vucinic choose to stay.
Both players have been linked with moves away from Roma this summer.
"De Rossi is calm," Juan said. "He's working with a great deal of enthusiasm and he has lots of quality.
"He is a leader and we want him to continue with us."
While it's understood that De Rossi wants to remain in the Italian capital, Juventus-target Vucinic has asked for a transfer.
"He's certainly working hard, but I can't really say any more about Vucinic than that," the South American noted. "I don't know what is going on in his head."
