Uefa opened disciplinary proceedings against Arsene Wenger, the Arsenal manager, after he used a mobile phone to give instructions to his first-team coach during a match while serving a touchline ban.
Wenger sat in the directors' box at Emirates Stadium during Tuesday's 1-0 home win over Udinese, the Italian side, in the first leg of their Champions League play-off, serving a one-match ban, and communicated with first-team coach Boro Primorac via his phone.
"According to the Uefa disciplinary regulations, a manager may not communicate with his team during the match for which he is suspended and may follow the game from the stands only," European football's governing body said in a statement.
Wenger, who said earlier this week he was confused by the rules, could now face a possible extension to his ban when the case is discussed on Monday.