Wisla Krakow defender Nikola Mijailovic has denied using racist language towards Blackburn's Benni McCarthy.
McCarthy has scored six goals for Rovers this season
Striker McCarthy, 28, claimed to have been racially abused by Mijailovic in Thursday's Uefa Cup tie.
"Both of us were swearing but there was no racist abuse at all," Mijailovic, 24, told Serbian newspaper Kurir.
"Investigation will show I'm innocent, everything can be seen on tape," added Mijailovic, who said McCarthy had been goading him from early in the match.
"Almost in the first minute he hit me very badly, it was a really inappropriate move for a football player.
"When I hit back, he started to bawl, to insult me, he even started to stick his tongue out at me.
We have written to Uefa, asking them to investigate allegations of racism
"During the game he used really numerous swear words during our duels.
"At the end of match I tried to ignore him, but he came closer and started to wag his hands in front of me.
"I couldn't stand all of that any more, so I've pushed him, and that was all.
"But, after that, I couldn't believe he was acting like a cissy. He claimed I used some racist comments - nonsense."
On Friday, the Football Association said it had submitted a formal complaint to Uefa, asking for an investigation into the allegations.
The FA confirmed: "We have written to Uefa, asking them to investigate allegations of racism."
Wisla claim they have already investigated the incident and found nothing to substantiate the claims.
Blackburn manager Mark Hughes asked Uefa to take action and the FA has added its support.
Uefa has warned it may be difficult to find any "hard evidence", but Hughes says: "Uefa should take as strong action as it is allowed to do.
"It is important we highlight these things because there is no place for them in sport or life. This needs to be eradicated."
Hughes said McCarthy approached Swedish referee Stefan Johannesson at half-time but the taunts continued.
The problem will be finding hard evidence to pass any sanctions
"Benni was upset by a number of personal comments directed at him by one of their players," added the Blackburn boss.
"It happened right throughout the game. Benni, to his credit, did not react to them and he highlighted the issue to a number of Krakow players and the referee at half-time.
"The situation still developed and there were more comments at the end of the game.
But Uefa spokesman William Gaillard admitted: "We have no reason to doubt Benni's word, he has been in the game for a long time now, playing at the top level.
"But the problem will be finding hard evidence to pass any sanctions."
The Football Association pledged to help Blackburn pursue their claims with European football's governing body.
"If this is the case it is very disturbing," said FA spokesman Adrian Bevington. "We treat these allegations seriously and we'll work with the club and Uefa.
"Unfortunately we have seen the recent trend where, when our clubs have gone away in Europe or the national side has gone away, we've seen them encounter situations of racism.
A spokesman for the Kick It Out campaign has urged Blackburn to pursue the case but Wisla's director of communications Vit Nielskee claimed the club had looked into the matter and there was no case to answer.