The visitors lead 0-1 after victory in the first leg last week but face a tough test having not won away at the Nou Camp since 2009.
Free-scoring Barca will fancy their chances of a turnaround having won the tournament for the past three seasons in a row, reaching the final in seven of the last 10 campaigns.
The match takes place on Thursday January 25. Kick-off is at 8:30pm UK time.
Which channel is it on?
The match will not be broadcast live on TV – but you can follow all of the action with Mirror Football’s live blog.
Will there be a live stream?
There is no official live stream of the game.
New signing Philippe Coutinho has been included in Barcelona’s 19-man squad for the first time since joining from Liverpool and could make his long-awaited debut.
Elsewhere, midfielder Andres Iniesta is back in training after a spell out injured and should feature, while defender Thomas Vermaelen is out injured. Samuel Umtiti is in line for his first start since the start of December.
For Espanyol, midfielders Manuel Jurado and Pablo Piatti are both injury doubts going into the game.