How do I resize an sprite on an axis independently of rotation?

If I get a square sprite, and shrink it on the Y axis it will become a rectangle. But if I rotate that sprite the rectangle rotates. What I want to do, is have the sprite resized on the screen Y axis not on it's local Y axis.

Hope it's understandable.

I'm trying to do perspective with it.

I need to do that at runtime, many ticks a second. Won't it be heavy?

Paster works pretty fast, you can update it on every tick.