Tare has commended the former Bayern Munich man for the effect he has had on the team, as well as his input off the pitch.
"With his experience, his calmness, his desire and his determination," he told lazionews.eu. "He has become critical both on and off the field.
"It was difficult to bring him to Rome, and we relied heavily on his willingness to accept a very difficult challenge.
"In economic terms, what we were offering was not comparable to what others offered."