McGhee will take charge of the Dons for the first time in a competitive game and while he knows that the name of Sigma may not whet the appetite too much, he is aware of how important a game it is for the Pittodrie club.
"The game itself does not hold the excitement that maybe an Atletico Madrid or Bayern Munich had, but that makes it all the harder because the expectation is there," he told Aberdeen's official website.
"I feel this is a game where the fans are crucial, far more even than if we were to get through and play the likes of Valencia, because those types of games, the atmosphere is automatically there.
"It is a good team that we are playing and we need as much help as we can. The supporters mustn't come here simply expecting us to win. They must come here to help us beat Sigma."