Rafa Benítez says Chelsea players have been stretched by their busy schedule. guardian.co.uk

Chelsea's players and staff have been warned to be more careful after an instruction sheet explaining tactics was found by journalists from the Brazilian website Globoesporte following the Club World Cup final.

Rafael Benítez's side were beaten 1-0 by Corinthians in Yokohama on Sunday, but after the team had left the stadium journalists found a crumpled piece of paper among litter in a bin.

The sheet detailed which Corinthians players should be marked at corners and said in large red capital letters to "be aware of counter attack" while pushing forward and to "immediately [push] up after we clear first ball" when defending set pieces.

The instructions are understood to have been left in the changing room by a member of staff, although the details were match specific and the club are not overly concerned as the revelations will not jeopardise any future games.

However, Chelsea have reminded their staff and players to be more vigilant so not allow any internal team instructions to be revealed in the future.

Globoesporte said the sheet was found "among sandwiches, energy drinks and broken sports equipment … the British left in the dressing room simple notes about O Timão [Corinthians] and detailed explanations of what each player should do at set pieces."