Papiss Cisse has been left out of Newcastle United’s pre-season tour of Portugal as the argument over the club’s new shirt sponsor escalates.

Tensions between player and club are now at an all-time high, resulting in Cisse staying in England and training alone while his team mates jet off to Portugal to continue their pre-season against foreign opposition.

Cisse cites his religious beliefs as his reason behind the decision to boycott the new “Wonga” sponsor and discussions between the striker and the club have not culminated in a compromise. The Senegal international is a devout Muslim and thinks the sponsor – a short-term loan company – promotes the borrowing of money, something Muslims are against.

The 28-year old has offered to wear an unbranded shirt or have one replaced with a charity logo but the club has refused to budge on their stance, remaining firm on their plans for the sponsor – which is worth £8m per annum – to stay.

What makes it hard to digest for some Newcastle fans is that the club’s other Muslim players have had no problem accepting the Wonga sponsor. Hatem Ben Arfa, Moussa Sissoko and Cheick Tiote – arguably three of the Magpies’ best players – are all getting on with the decision and not kicking up a fuss.

However, Cisse’s beliefs seem to be different to those of his fellow Muslims and the argument is threatening to boil over as the start of the new Premier League season draws nearer.

Rumours are now starting to surface about the former Freiburg man’s immediate future, with some saying Darren Bent is to be brought in as his replacement before the transfer window shuts.

Only time will tell as to whether this mess gets sorted out amicably or not, although the situation looks bleak if both parties continue their stubborn stances.