Vilanova is currently undergoing treatment for cancer in the American city and is out of action.
"His health is the most important thing," Rosell told Barca's official website on Tuesday.
"It takes priority, it's more important than tonight's match or tomorrow's titles.
"We miss him as a person and a professional. [Jordi] Roura will continue managing the first team because we have a lot of confidence in him."
Vilanova could reportedly remain in New York until the end of March.