Vieira joined City from Inter Milan in the January transfer window.
The Frenchman made his first star for City in the 2-0 win over Bolton on Tuesday.
“I really believe we are strong enough to finish in the top four,” said Vieira.
“There’s still a long way to go. It’s important to win each game and see where we can go, but we are very confident.
“This was my first 90 minutes for quite some time and I feel all right. It was very physical, of course, and when you play against Bolton you expect this kind of game.
“The important thing was to win the game after the defeat at Hull and we are very pleased to have done that.”
