@hjs For sources like these (and other FC Homburg players you've cut) you can crop the image closer to the top and bottom edges, there's no need to leave so much blank space above the head and so much neck below the chin - you only need to leave 2 or 3 pixels space.
In future, it's best to crop the image to the red area, cropping out the black area:


Since cropping to the red area in this source gets rid of the collar, it's easy to follow this method (video version) to move the collar up, like so: