Europa League important to Vieira
Vieira has made just two starts this season, against FC Timisoara in the Europa League qualifier and a scoring appearance in a 1-1 home draw against Blackburn Rovers.
The veteran had to be content with a late appearance off the bench at Red Bull Salzburg in the opening group game, and he is eager to contribute more.
He said: "I have been happy with my form since start of season. It is difficult when you play one game every month. I need to work harder than everyone else to show the manager can count on me. I just want to enjoy myself. I am involved in a fantastic challenge with this club and really want to be part of it.''
Juventus have suffered an inconsistent start to the season under new coach Luigi del Neri, and Vieira is confident that City will take points at Eastlands against his former side.
"I think they are going through a difficult period. Maybe it is not the best Juventus side in the last few years but they are still a really competitive team," said Vieira. "It will be difficult for us to find the space to play but we have players who can give them problems as well. Our strength is the squad. We can be competitive in every competition we are involved in.''
Manager Roberto Mancini added: "We are working to improve, like Juve. We need time. We have the same targets. It is an important week. It is important after beating Chelsea we try to beat Juve and then deal with Newcastle. They will be two difficult games.''
Mancini did not rule out the possibility of coaching Juve one day.
"Why not, football is like that, '' he said. "I have never been an enemy of Juventus. I was a huge fan for years when I was a child so I have great respect for the club and the players. It will be a special match as it is the first time I am coaching an English team against Juventus. Obviously I miss home as anyone would but I am happy here. This is where I am living and working.''
Del Neri wants his side to focus fully on City and put thoughts of Sunday's Serie A showdown with Inter Milan on the back burner. After managing only a home draw against Lech Poznan in the opening group game, Del Neri knows there is little room for error.
He said: "I am only interested in the game against Manchester City not the following match. We will see then if we have improved. A new team always make mistakes. You not only need to fix the problems but also to focus on what you do well.''
Veteran striker Alessandro Del Piero said: "Manchester City are in excellent shape and it will be very hard for us. It always is when you are in England. They have invested heavily and one of the reasons they can be successful is that they have a great squad of players.
"We have a good base to build on and are at the beginning of a journey. Hopefully we our results will improve as time goes on.''