Hibernian could have to overcome their 1-0 deficit against Brondby with Neil Lennon in the stand after their manager was handed a one-match touchline ban.
Lennon will have to overturn the ban next Thursday, on the day his side face the Danes in Copenhagen in the second leg of the Europa League second-qualifying round.
Lennon was sent to the stand in the 31st minute at Easter Road after protesting over a disallowed goal, when Jason Cummings was harshly ruled offside.
A UEFA statement read: "Proceedings have been opened against Hibernian FC head coach Neil Lennon, following his dismissal from the bench at last night's UEFA Europa League qualifying match against Brondby IF.
"This means that he is automatically suspended for the next match.
"The UEFA Control, Ethics and Disciplinary Body will deal with this case on 21 July."
After the match, Lennon hit out at referee Juan Martinez Munuera, claiming he wanted to be the "star of the show".
He added: ''I want to appeal it, because it's just a piece of nonsense. It's the first time in Europe that I've been sent to the stand so I'm really irked by that."
Lennon saw enough in the game to give him hope of securing a third-round tie with Hertha Berlin as Hibs responded well to the loss of a goal after 16 seconds, following goalkeeper Otso Virtanen's blunder.
"The tie is in the balance but we know we have to go there and score," he said.