Newcastle's Muslim stars may refuse to wear the club's new sponsor on their shirt.
In the latest controversy surrounding the club's deal with loan company Wonga, Newcastle now face a tricky situation with several of their senior players.
Under Sharia law, Muslims must not benefit from either lending money or receiving money from another person - meaning that interest is prohibited. Interest is not paid on Islamic bank accounts or added to their mortgages.
Senegalese duo of Demba Ba and Papiss Cisse Ivorian midfielder Cheick Tiote as well as Frenchman, Hatem Ben Arfa are all practising Muslims.
They may follow the stance of former Tottenham and West Ham striker Freddie Kanoute, who refused to wear the logo of gambling website 888.com on his Seville shirt over his religious beliefs.
Kanoute instead wore an an unbranded top in Spain, although he agreed to wear the logo during training.
Wonga, whose four-year deal takes over from Virgin Money at the start of next season, has already drawn fierce criticism from other quarters for the huge interest charged on 30-day loans
Should a Newcastle fan accept a loan to buy a £50 club shirt, they would have to repay £71.92 after a month with a rate equivalent to 4,212 per cent per year.
FA general secretary Alex Horne said: 'The Football Supporters’ Federation of Britain told us in no uncertain terms it’s not appropriate, (Sunderland non-executive vice-president) David Miliband has told us he does not think it is appropriate.
Newcastle and Wonga have attempted to take the sting out of criticism by announcing that the club's ground will revert to its former name St James' Park.