The 22-year-old, who is on a season-long loan from Benfica, has been nursing a hamstring problem since the end of December.
"The plan was for him to play 70 to 75 minutes but he felt well and to get 90 minutes under his belt is even better," said first-team coach Dietmar Hamann.
Vitor, recruited by former boss Paulo Sousa, will do well to unseat the central defensive partnership of Sol Bamba and Ben Mee, but Hamann added: "The manager has watched him play and there are a lot of games still to go.
"Things can change quickly in football. You can get suspensions and injuries and then the situation changes."
Meanwhile, the 1-0 victory over Southampton on Wednesday saw a first appearance for Vitor's Portuguese compatriot Ricardo, who has joined City until the end of the season after being released by Real Betis.