The largest online fantasy football kit design site has thousands of so called logo copyright infringements every day. As far as I’m aware Puma, Nike, Adidas and various other companies obviously turn a blind eye to it. They probably see it for what it is, just some amateur kit designers having a go at designing their ideal team kit.
The only way round it would be to design your kit with manufacturers badges and include a link to the fantasy kit site. That way, if Puma and Motherwell have a problem they can take it up with them and not SteelmenOnline.
Football Shirt Culture Fantasy kit Design Site