Is the ball on it’s own layer in photoshop ? And does it have transparancy there ?
If not, you need to make an alpha-channel for the yellow ball.
Ypu can do this in After effects, but I would do it in Photoshop:
I’d suggest duplicating the blue channel and using that as an alpha, you might want to tweak the levels;
then once the yellow ball has it’s own layer, don’t forget to “remove white matting” from that layer.
In After effects import your .psd as a composition, or import only the ball-layer.
Now you should have transparancy.