The Blues have already strengthened a squad that finished third last season and further signings are expected as skipper Carlos Tevez edges closer to the exit door. Vidic is anxious not to be seen spending time worrying about United's rivals as the countdown to a new campaign begins, but is certain City will pose their biggest challenge yet for major honours.
"It is clear Manchester City have the money and they will sign new players," said the Serbia defender. "They will definitely be in position to fight for the league."
He added: "But we have to focus on ourselves. We have to think about what happens at our door, not our neighbours', and I believe we have enough good players and a good team to challenge for the trophy."
United have endured a strange summer. Within a week of lifting a record 19th title, they suffered that chastening Champions League final defeat to Barcelona. It leaves supporters unsure about whether to call for additional reinforcements or be happy at the three new faces Sir Alex Ferguson has already brought in - David de Gea, Phil Jones and Ashley Young.
A replacement for now-retired Paul Scholes is the biggest demand, although Vidic can see no reason to panic.
"We still have good players," he said. "We have important players who can play in that role. If you look at what we did over the last few years and how many trophies we have won, a lot of players have played in that position.
"It is the gaffer's judgment about who we need and what we need. As players, we just need to be healthy and work hard."
However, until the ghost of Barcelona has been exorcised, doubts will remain - much as Vidic would prefer to ignore them.
"I don't know why you are always asking Manchester United players how we are going to bridge that gap," he said. "Like I say again, this team is successful. We are doing some good things. We don't have any problem with the Barcelona players. We respect them but we are not scared to play against them."
Source: PA
Source: PA