Brazilian wingback Roberto Carlos on Thursday criticized fans of the Russian national team for their hostile reception of Yury Zhirkov during Russia's 1-0 defeat of Serbia on Wednesday. Despite a bright performance, Zhirkov suffered incessant boos and whistles from a 20,000-strong crowd following his move this week from Chelsea to Russian Premier League side Anzhi Makhachkala. The venue for Wednesday's game was the home stadium of Lokomotiv Moscow, a fierce rival of CSKA Moscow, Zhirkov's club before he joined Chelsea. Roberto Carlos, a teammate at Anzhi, told RIA Novosti that fans need to understand "it's your team. You should applaud the players on your side, not whistle at them." "It doesn't matter which club [Zhirkov] plays for, it only matters that he plays for the national team." Roberto Carlos is the highest-profile football figure to come out in defense of Zhirkov after Russia coach Dick Advocaat said he was "disappointed" with the reception. Football officials have condemned the aggression as unprecedented and threatened to take action against the perpetrators. Anzhi have brought out envy among many Russian fans for a spending spree funded by new billionaire owner Suleiman Kerimov that has helped catapult them into the top half of the Premier League. Media reports say Inter Milan's Cameroon striker Samuel Eto'o is on the verge of signing a four-year deal. Zhirkov was slammed in some quarters for selling out by joining Anzhi on a four-year contract for an undisclosed fee, but the player said he needed playing time that he was not getting at Chelsea. Injuries and poor form meant he failed to settle at Stamford Bridge after joining in July 2009 for 18 million pounds. Zhirkov could make his Anzhi debut against Spartak Moscow on Sunday. Roberto Carlos, who joined Anzhi from Corinthians in February for a fee thought to be around 10 million euros, has himself been the target of aggression from the Russian stands. During a Russian league match in May he left the pitch in protest after a banana thrown by a fan of the opposing team Krylya Sovietov Samara landed near him.