Toure and his brother Kolo, the defender, are now back at City after a month away playing in the African Nations Cup with Ivory Coast.
Roberto Mancini's men have been unbeaten in their absence but draws in the last two fixtures against QPR and Liverpool have seen them slip nine points behind Manchester United at the top of the table.
After memorably recovering from an eight-point deficit to win the title last season with six matches remaining, Toure is sure there is enough time for City to turn it round again with 13 still to play.
The midfielder told the club's website, www.mcfc.co.uk: "We are further behind than we'd like, of course, but all we need to do is think about last season to know what is possible.
"My friends are all here and are happy to see me and we are like a family or brothers who will all fight together - and that is a very important thing to have.
"United have a strong squad and, on paper, they have an easier run in than we do but the title race is a long way from finished.
"It only takes a couple of results to go our way and we're right back in it - I'm sure we'll come back."
City travel to Southampton on Saturday hoping to cut the gap to seven points ahead of United's clash with Everton on Sunday.
The return of the Toures gives City a timely lift in two areas of the field.
Yaya's dynamism in midfield has been missed, particularly in the past week, while Kolo will increase defensive options.
City have been short at the back with influential captain Vincent Kompany having missed the past two games with a calf strain.
Kompany has not definitively been ruled out of the trip to St Mary's Stadium but Mancini has said it is likely the Belgian will be out until after next week's FA Cup fifth-round clash against Leeds.