The 28-year-old was due to join the team with the other Chelsea players who participated in the World Cup semifinals and final -- he played in the final penalty shootout loss to Italy -- and be available when Chelsea faces the Major League Soccer All-Stars on Saturday in Chicago.

Gallas, who has indicated he would like to leave the club as he does not like playing full-back instead of his preferred centre-back position, requested extra-time off following the World Cup but was informed he should still report to Los Angeles on the date previously agreed.

His failure to report has club officials considering further disciplinary action as a consequence.

"William Gallas will not be joining up with Chelsea on the pre-season tour of the United States," read a statement from the club.

"William requested extra-time off following the World Cup but was informed he should still report to Los Angeles on the date previously agreed with him. He did not report and further action will now be considered by the club as a consequence.

"Pre-season training and the tour is about building team spirit among our squad and extra leave is only granted for valid football-related reasons."

Gallas, who signed from Marseille for 6million pounds five years ago, has one year remaining on his Chelsea contract but talks are ongoing over a new one as the Premiership champions have insisted he is not going anywhere.