The former Spain international admitted that he struggled to follow Bayern Munich's win over Werder Bremen on Saturday because of his devastation over the loss of his friend
It was announced on Friday afternoon that Vilanova had passed away at the age of 45, after losing his lengthy battle with cancer.
Just a day later, Guardiola led Bayern Munich to a 5-2 victory over Bundesliga rivals Werder Bremen and admitted afterwards that he had had trouble concentrating on the game because of the loss of the man with whom he won two Champions Leagues and two Club World Cups.
"It was difficult for me to follow the match today [Saturday]," the 43-year-old confessed. "Tito was more than a friend.
"The sadness I feel will accompany me for the rest of my life. We were young, we wanted to beat the world, and we did."
As for the game itself, Guardiola was reluctant to read too much into what was ultimately a resounding victory ahead of next week's crunch Champions League clash with Real Madrid.
"We won, that's good before our 'final' against Real Madrid," the Catalan confessed. "But that will be a totally different match.
"But I trust my team. I hope we can do it [on Tuesday], together with our fans."
Madrid trail 1-0 after last Wednesday's first-leg meeting with Madrid at the Santiago Bernabeu.