Luis Suarez must serve the entirety of his four-month ban for biting Italy defender Giorgio Chiellini after an appeal against the length of the suspension was rejected by the Court of Arbitration for Sport. However, the striker has been cleared to train with new club Barcelona having originally been barred from entering football stadiums. The decision will come as a hammer blow to Suarez, whose lawyers had argued Fifa's decision to ban him "from all football related activity" was excessive and were previously confident his suspension would be halved upon appeal. Suarez, Barcelona and the Uruguay FA also argued that Fifa's extension of the ban to cover domestic matches was disproportionate as the biting incident took place during international duty for Uruguay at this summer's World Cup. The decision means Suarez is still banned until the end of October, but is still in line to make his debut for Barca in La Liga's first El Clasico of the season against Real Madrid on the 26th. The player will also be relieved he is now able to train with the Catalan club during the length of his suspension having been previously prohibited from entering stadiums. The four month ban handed down on Suarez was the biggest in World Cup history. His bite on Chiellini was the third such incident of his career having been punished for similar offences in the past, after biting PSV Eindhoven's Otman Bakkal on the shoulder while playing for Ajax and Chelsea's Branislav Ivanovic while at Liverpool. The Reds sold the striker to Barcelona this summer for £75 million.