Stamford Bridge change stance on rascism.
Chelsea have complained to the Malaysian Football Association about the anti-semitic abuse aimed at midfielder Yossi Benayoun.
The Blues initially dismissed the booing as a result of a bad tackle by the Israeli during the pre-season game against Malaysia XI.
But having reviewed the game the west London club have changed their mind with the club set to fly home at the weekend.
A statement from the club read: “Notwithstanding most fans behaving appropriately on the night, we believe Yossi was subjected to anti-semitic abuse by a number of supporters at the game.
“Such behaviour is offensive, totally unacceptable and has no place in football.
“The club did not make representations at the time as it was initially unclear as to the nature of the abuse Yossi received, as several players from both teams experienced similar treatment, sometimes louder and longer.
“However, having taken time to consider the issue fully, it has become apparent that a formal complaint was necessary.
“Our stay in Malaysia was, on the whole, a very positive experience for all the team travelling on the pre-season tour.
“It is a shame, therefore, that the behaviour of a minority of supporters is also a memory we take away.”
The Malaysian FA said they have not received the complaint.
Chelsea have one more match left of their Asian tour to play – against Aston Villa in Hong Kong on July 30 – before they return home.