Vicario produced a couple of excellent saves to keep out Manchester City, as Ange Postecoglou's Spurs claimed a stunning 4-0 victory over the champion at the Etihad Stadium.
However, the Italian needed treatment during the first half after colliding with Savinho, and it has now been revealed he played the final hour of the match with an ankle break.
The former Atalanta shot-stopper wrote on social media: "Sometimes football gives you its highs, and sometimes it challenges you in ways you don't expect.
"I played 60 minutes at the Etihad with a broken bone in my ankle, giving absolutely everything I had for the team.
"Unfortunately there was no way around this one. I needed surgery. I'm disappointed I won't be able to help the team for a while."
Tottenham did not put a timescale on Vicario's recovery in a statement of its own, saying: "We can confirm that Guglielmo Vicario has undergone surgery for a fracture of his right ankle.