Arsenal winger Theo Walcott angered Tottenham Hotspur fans while being carted off on a stretcher during his side's comfortable 2-0 win over their London rivals in the FA Cup on Saturday.
Arsenal were already heading into the fourth round draw, with goals from Santi Cazorla and Tomas Rosicky, and the mood of the visiting suppporters was not helped by Walcott gesturing the scoreline with his fingers after injuring his knee.
His actions could yet take some of the gloss off an impressive Gunners display if the FA take a dim view of his actions, although Arsenal manager Arsene Wenger played down the incident which saw a grinning Walcott showered with coins.
"The doctor said to me that the coins were already raining over his head and they had to protect him before he made the gesture, but what he did was not offensive," Wenger told reporters.
"I don't think the FA will take any action, I've seen the pictures and he's not being aggressive, he's smiling. I hope he's not banned or doesn't miss any matches because of the injury.
"With Theo, he has a knee problem. We don't know if it's a stretched ligament or just a kick, he got two kicks on to his knee," added Wenger. "Of course, if we lose Theo for a longer period, it's a problem."
However, he did have some positive news on Denmark striker Nicklas Bendtner, who was injured scoring Arsenal's first goal in Wednesday's 2-0 Premier League home win over Cardiff City.
"For Bendtner, it will be for one month, we expected it could have been more, but we had good news," said the Frenchman.
Arsenal's victory over their arch-rivals Tottenham handed Wenger's opposite number Tim Sherwood his first defeat since being permanently appointed as the club's head coach last month in place of the sacked Portuguese Andre Villas-Boas.
Cazorla's arrowed drive after 31 minutes and a second goal by Rosicky just past the hour mark following a mistake from Tottenham left back Danny Rose on the halfway line when he lost possession to Rosicky, secured Arsenal's place in the last 32.
Czech international Rosicky's goal all but ended the contest after he ran half the length of the pitch before lifting the ball over keeper Hugo Lloris with Kyle Walker chasing him down.
Mainly restricting Spurs to half-chances and the occasional counter-attack, Premier League leaders Arsenal held out for a deserved win even though they played the last few minutes with 10 men after Walcott was carried off with a knee injury.
Sherwood said he had not seen the incident involving the England winger and wanted to focus on his team's disappointing performance which ended their interest in the domestic cups following a League Cup quarter-final loss to West Ham United.
"Obviously it was a disappointing result but in the second half we kept possession better without opening up Arsenal too many times," 44-year-old Sherwood, appointed on a permanent basis two days before Christmas, told a news conference.
"We had a few half-chances that, if we had taken them it might have been a different story, but they are top of the league for a reason because they are very, very good, but I don't think we disgraced ourselves.
"We've had six games in 17 days with probably the smallest squad in the league right now with all our injuries at the moment, and we showed great character, but we were fatigued and a little bit of sharpness was missing."
Arsenal, seeking their first silverware since a 2005 FA Cup triumph, were the better team in a typical blood-and-thunder derby despite the absence of strikers Olivier Giroud and Nicklas Bendtner, midfielder Aaron Ramsey and defender Kieran Gibbs.
Walcott and teenage German striker Serge Gnabry caused problems at the heart of the Tottenham defence, which looked vulnerable almost every time Arsenal poured forward.
Spurs, whose form has improved dramatically under Sherwood were always second best after a bright start, with striker Emmanuel Adebayor, who has recently played a key role with four goals in five games, largely anonymous against his former club.
"I thought we played well in defence and in attack and controlled the game which was played at quite a pace," Wenger said. "Our game was based on quick, sharp passing and we were dangerous."
Since losing 2-1 at home to West Ham in the League Cup, while Sherwood was still caretaker, Tottenham have taken 10 points out of 12 in the Christmas holiday period, including a 2-1 win at Manchester United, and will now focus on a top four league finish and progressing from the Europa League last 32.
Arsenal's quest for domestic and Champions League honours will be given a boost by another win over their arch-rivals.