Patrick Vieira claimed Manchester City are still in the race for the Barclays Premier League title after sealing his move from Inter Milan today.
France international Vieira, who becomes new Blues boss Roberto Mancini's first signing, has signed a six-month deal at Eastlands with an option for a further year.
The 33-year-old former Arsenal midfielder, whose deal at Inter was due to expire in the summer, also insisted City were not getting a player past his best.
"I'm really delighted, really happy, really proud to be back. City are a really ambitious club," said the France international.
"I am very confident, I believe in myself.
"I know I am not 20, but I am not 40-45. Overall I am really motivated."
"I know I can give something to this club and hopefully we will be successful this year.
"When you look at the players the club has got you can achieve a lot. I strongly believe we are not out of the race to win the title. I am sure we can do it."
Vieira admitted the move was motivated in part by his desire to secure first-team football to work his way into the France squad ahead of the World Cup finals.
"I hope that the club as well will give me the opportunity to get back to the French national team," he added.
Vieira feels City are a club which are capable of winning trophies.
He added: "I chose City because I really believe something can be achieved at this club and I want to be part of it."
Mancini, who coached Vieira at Inter, said he saw the midfielder as a regular player.
"Patrick for me is a big player, an important player," said the Italian.
"Patrick won with Arsenal, with Juventus, with Inter a lot of trophies. I think he must continue at City.
"He can help us to improve our performance, for sure."
It remains to be seen whether he will be match fit to face Blackburn on Monday, having taken in kick to the calf in his final appearance for Inter on Wednesday.
"I don't know," added Mancini. "We will see and then decide."
Vieira knows, though, he will have to prove he is worthy of a place in the City starting line-up.
"I have to show the manager I deserve to play, show to the players I deserve to play," he said.
"I have to show in every training session I deserve to play. It will not be easy. I will have to fight for my place."
The former Arsenal captain is looking forward to resuming his rivalry with Manchester United.
"It has always been exciting to play against United," he said.