Roberto Mancini’s men have been unable to keep pace with the Red Devils, who have been setting the pace in consistent fashion this season and top the table with 16 games left.
United look to be on course to claim their 20th top-flight crown but Vieira believes City still have a “good chance” of pipping their local rivals to the title.
“There’s still a long way to go. We still believe we have a good chance to catch them,” City football development officer Vieira told talkSPORT.
“It will be more difficult than last season, of course, but we have to give it a go.
“When you look at Chelsea, ourselves and Manchester United, I think all three teams have a chance.
“Manchester United are in a really good position but what is interesting in this Premier League is anybody can drop points and the door is still open for us.
“We just have to look at ourselves. We know what we have to do and we will keep fighting.”
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