Didier Drogba and Michael Ballack may face sanctions, warns Uefa official

• Conduct of Chelsea players and club itself under scrutiny
• Decision on Darren Fletcher suspension due tomorrow

David Taylor, the general secretary of Uefa, believes Didier Drogba's midweek outburst was a blow to the 'Respect' campaign and has admitted Chelsea may have to wait several weeks before discovering his fate.

Uefa is collecting evidence before deciding whether to charge Drogba – and possibly his team-mate Michael Ballack and Chelsea themselves – for the ugly scenes that marred Wednesday's Champions League exit at the hands of Barcelona.

"It was not pleasant to see, not the sort of example one wants," said Taylor, whose employers, like the Football Association, have striven to improve conduct towards officials. "Uefa has a respect campaign and this just flies in the face of these worthy endeavours."

Drogba harangued the Norwegian referee, Tom Henning Ovrebo, after the final whistle for failing to award a penalty to Chelsea despite several strong appeals and then swore audibly at a television camera before leaving the pitch.

The German midfielder Ballack also drew criticism for chasing and shouting at Ovrebo in the dying moments of the game while the London club could face action for failing to control their players.

Taylor admits Uefa "expects to take action" of some kind, although he was "pleased" with the apology issued by Drogba, through the club's website, for his behaviour. He would not, however, be drawn on the possible outcome of Uefa's ongoing investigation.

"The proceedings are instigated by Uefa but the decision is made by the control and disciplinary body, which is quasi-independent," he told BBC Radio Five Live's Sportsweek programme. "They look at all the evidence, including video evidence, the objective and subjective factors, the mitigating circumstances – if any – before they come to some judgment.

"You can speculate, will somebody get this sentence or that sentence? It's pure speculation," Taylor added. "At the moment I'm not going to confirm whether it's Drogba, Ballack, Chelsea, all three or others – these are the things we're looking at this weekend. It could be a number of weeks yet before such a decision will be made."

Uefa will also consider the fate of the Manchester United midfielder Darren Fletcher at a disciplinary meeting tomorrow after his semi-final sending-off against Arsenal. Replays appeared to show his dismissal, which has ruled him out of the final against Barcelona, was harsh and United have asked Uefa to consider quashing his ban.

But Taylor believes it might set a dangerous precedent if Uefa panders to the English and European champions. "Uefa gets accused of a conspiracy in terms of trying to engineer a final which doesn't have two English teams in it," he said. "The more you use discretion the more you leave yourself open to ridiculous accusations like that."

He added: "The matter is being considered by the disciplinary body tomorrow. But as a rule, a player who is sent off will automatically miss the next competition match. We try to be as open and responsive as possible but we have a duty to all the other clubs, as well as football itself, to apply the competition rules."