Roberto Mancini's are currently first in the league after an excellent first half of the season.
Barry told The Mirror: "The game coming up against Spurs is a huge one in the title race. The lads aren't thinking about the money the club has spent at all - they're thinking about winning the league.
"That's the pressure - trying to win the title. Managers can see when pressure is affecting players, and that's where they must make their decisions. Pressure can affect some players more than others."
Barry signed for Manchester City in 2009 from Aston Villa.