Why are current images with large image sizes rejected?

Because while the image dimensions are large, the face in that image is still less than 200px tall, which means it would lose quality if it is resized for a 250px cutout.

Because I've grown tired of telling you that uploading images which aren't that large will not result in improvements.

The image might be 618x888 in size, but the area which the face takes up is much smaller than that, as per the below. It's less than 250 pixels high, which means that any cut will need to be upscaled to fit the 250x250 canvas we aim for, which means that its quality will therefore be slightly decreased, which means it's unlikely that it'll be of a similar or better quality to the current cut (which is very similar and of a very good quality already, and only a year old anyway), which means there's little point in cutting it in the first place.

I uploaded other football player pictures from the same picture, it was cut to the same size

the club shared player faces like this, all the same style and size 🙂

In my opinion, there was no need for that image to be cut either. Once it was cut, of course I'll take it, but there was really no need for it to be honest. We have hundreds of pending images - why should cutters spend their time on that image when more pressing ones are available?