Aston Villa's chances against Manchester City have increased significantly-maybe even all the way to remotely plausible!-with word that striker Sergio Agüero will miss Wednesday's game at the Etihad due to a groin strain suffered last weekend against Everton. City will now have to fall back on depth players such as Edin Džeko, Álvaro Negredo, and Stevan Jovetić as they take on the monumental task of breaking down Villa's stalwart back line.
In seriousness, while City's remaining firepower is more than ample, they are a legitimately different team without Agüero. "Different" is not inherently the same thing as worse, but Villa likely match up more favorably against City's other strikers. That doesn't change the overall gulf in talent, but it does make City's ability to carve up a bunkered-in Villa defense slightly less of a foregone conclusion.
Still, Villa's greater concern against City is and always has been their ability to put the ball in the net themselves. Agüero's absence does nothing to change that. City will score-most likely multiple times-no matter who they're playing up front. Not having to worry about Agüero is certainly preferable to the alternative, in the same way that dealing with 10 rabid hyenas is preferable to dealing with 11; it's the better option of the two, but not really cause for breathing a sigh of relief.