Barcelona manager Ernesto Valverde has said it is "essential" for his team to claim an advantage in Thursday night's Copa del Rey semi-final first leg against Valencia at the Camp Nou.
After overcoming a first leg deficit to Espanyol in the quarter-finals, Barca next face a resurgent Valencia side, who appear to have banished the difficulties of recent seasons to sit third in the Primera Liga table.
Successive league defeats to Las Palmas and Real Madrid have halted Valencia's progress somewhat but Valverde is wary of the threat posed by Marcelino's side.
"When it came out in the draw we already knew that they would be a tough opponent, who are now having a great season," the Spaniard said. "It is essential for this first match to try to get a good result because then (in the second leg) at their home they are a strong team.
"It is also true that they are strong away from home, and that they tend to score, so keeping a clean sheet, would be important. Let's see how it goes. It is an open knockout match, beautiful for the spectator, there are two great teams. And of course complicated for them and complicated for us."