(CNN) -- Manchester City have lodged an official complaint with European football's governing body after striker Mario Balotelli claimed he was racially abused during Thursday's match away to Porto.
City came from behind to win the first-leg Europa League tie 2-1 in Portugal, but the English Premier League leaders approached UEFA after the match when Italy international Balotelli complained of being subjected to racist chants from fans.
UEFA confirmed to CNN Friday that City's complaint had been received, but said a decision on whether to launch an investigation would not be made until the match delegate's report had been received.
Despite reports that Ivory Coast midfielder Yaya Toure, playing his first match since Sunday's African Cup of Nations final loss to Zambia, was also subject to abuse, a City spokesman said the club only knew of Balotelli's complaint.
"I didn't hear this because I was concentrating on the game. I don't know if (it happened) to Mario and Yaya," City manager Roberto Mancini was reported to have said by the Press Association.
Mancini, who also coached Balotelli when they were both at Inter Milan, praised the 21-year-old for maintaining his focus during the game.
Balotelli has had a checkered disciplinary record since arriving in England in 2010 and has just returned from a four-match ban for stamping on Tottenham Hotspur's Scott Parker during a league match in January.
"I think Mario did very well, he played very well," Mancini said. "He was calm and it is important he continues like this.
"I think this provocation can happen every game. For this reason I spoke with Mario before the game. I said, 'Mario think and play, think what you should do during the game.'"
Balotelli, an Italian of Ghanaian descent, has been on the receiving end of racist taunts in the past when representing his country. He was repeatedly jeered when he made his second appearance for his Italy in a friendly match against Romania in November 2010.
Toure said after the Porto match that one of the reasons why he enjoys playing in England is the lack of racial abuse from fans.
"That's why we all like the Premier League, because it never happens there," Toure told Sky Sports. "Maybe in foreign countries they don't expect black players.
"I think in future it will be okay, they will change their minds and the game will become more open. Football is football and the fans come to enjoy the game, and we don't want things like this to happen."
Despite Toure's claims, the English game has been hit by several recent race-related incidents.
A police investigation was launched last month when a Liverpool fan was alleged to have racially abused third division Oldham's Tom Adeyemi during an FA Cup tie.
Liverpool striker Luis Suarez has also recently returned from an eight-match ban for directing a racial slur at Manchester United's Patrice Evra.
In July, England captain John Terry will face trial for alleged racial abuse of Queens Park Rangers defender Anton Ferdinand.
Manchester City's Micah Richards and Newcastle's Sammy Ameobi have received racist abuse on microblogging website Twitter, as have former Everton striker Louis Saha and Scotland-based players Maurice Edu and Kyle Bartley, both of Rangers, and Inverness' Gregory Tade.