Vilanova, who replaced Pep Guardiola last summer, has missed the majority of Barca's matches this year as he undergoes treatment to combat throat cancer after having surgery in December, with his assistant Jordi Roura taking charge.
Forty-four-year-old Vilanova is set to return to Barcelona at the end of the month, but it remains to be seen when he will be able to resume his full responsibilities.
There are no doubts in Zubizarreta's mind about Vilanova's longer-term future at Barca, though.
When asked if Vilanova will be Barca coach next season, Zubizarreta told Catalan radio station RAC1: "Yes, absolutely."
Zubizarreta said: "Tito will arrive at the end of March. I don't know if it will be the March 25th, we have to be prudent with the date.
"After that, he will set the agenda. If he wants his first day to be in the morning, afternoon or evening, then fine."
He added: "Tito is very well. His appearance, his mood, weight, everything. If you saw him in the street, aside from his scarf, you would think he is in perfect health.
But we know that these types of treatment wear you down. We're happy with how the process is going."
Barca this week sealed their place in the quarter-finals of the Champions League after overcoming a 2-0 first-leg deficit to beat AC Milan 4-2 on aggregate.
They are also 13 points clear of second-placed Real Madrid in the Primera Division.