Copenhagen welcome Chelsea to the Parken Stadium having not played since December 7 due to the winter break, meaning they will be fresher than their glamorous opponents.
However, this can backfire as it always takes time to get up to match speed and with Chelsea having played two matches in the last eight days, match fitness could play a key role in the first leg.
The Danes have been in unstoppable form all season, they are undefeated in 19 games and have a 19 point lead at the top of the table.
Domestic domination, which has seen them take the title seven of the last nine years, has not always shown in European competition, but this year the Parken side look a different proposition.