Inter Milan's Brazilian striker Adriano apologised for his sending off in the final moments of the 0-0 draw with Valencia but said it was self defence.
The prolific Brazilian was dismissed in injury time of the Champions League game on Tuesday which secured Inter a place in the knockout phase of the competition.
There were ugly scenes of pushing and shoving involving several players after Adriano lashed out at Valencia's Marco Caneira.
"I apologise to the club, my team mates and the fans. I was wrong to react," Adriano told the club's official website.
"The sending-off, which is the first in my career, is a burden for me because I always want to give something to Inter and not leave them with a man less on the pitch.
"But, as I explained to the referee after the match, it was legitimate self defence," he added.
Inter coach Roberto Mancini said: "He was provoked. He took a slap and he is not the sort of lad to just do something like that".
Club president Giacinto Facchetti said that he and Adriano had spoken to Russian referee Valentin Ivanov after the game.
"The lad apologised for his reaction, but he also said that it was because he had been provoked several times and was slapped in the face by Caneira," said Facchetti.
"This is very clear from the television images, which the referee and UEFA delegate have seen.
"Indeed, they wanted the cassette with the images so they can make a better evaluation of the episode," added Facchetti.
Adriano faces a suspension, although with Inter already through to the next stage with two games still remaining, a ban of less than three matches would merely mean he sits out matches which are meaningless for the Italian side.
Valencia's Italian coach Claudio Ranieri, who is hoping Inter can help his team by beating German rivals Werder Bremen, said he had more reason to be concerned about the red card than his Inter counterpart.
"I think between myself and Roberto, I am the one who is more upset about Adriano's red card," said Ranieri.
"He will probably have to sit out the last two games but it would be better for Valencia if he played".
