The Catalan side dominated possession throughout the entire match, but was unable to muster up any kind of threat towards Christian Abbiati's goal.
Barca's lack of imagination in the final third proved to be detrimental as the hosts netted twice through Kevin Prince-Boateng and Sulley Muntari, leaving the Spanish side with a mountain to climb to reach the quarterfinals.
Speaking to the media, Roura bemoaned the scoreline, stating:"The result was a bit excessive, they only really had two chances. They defended well. It will be difficult but we're fully confident in our team and our fans."
Tito Vilanova's stand-in added that he believed that his side should have got something more out of the game, but insisted that it was important to quickly move on from the loss and look to the second leg.
"[The result] is what it is. Now we should let some hours go by, recover from this, and then move on."
The second leg takes place at Camp Nou in Barcelona in three weeks time.