According to current Porto keeper Iker Casillas, Real Madrid are more dangerous over the span of one game than their Catalan rivals, whereas Barcelona normally need two ties to dominate.
While not an elimination format match, the Blaugrana are well aware it is their last chance to take the LaLiga title race to the wire, and there is no room for error.
Nonetheless, the ex-Real legend believes Los Blancos have the upper hand because of this preference.
"In one-leg ties, Real Madrid inflict more damage than Barcelona," he said. "I hope that Real can win to secure the league a bit more, because they deserve it."
The shot-stopper first faced Barcelona back in 2000, and knows the Catalan side quite well, as he does his former coach Jose Mourinho."At the beginning there was a good connection with Mourinho," Casillas pointed out. "But in the end there wasn't a very good feeling.
"It is a bit like being in a relationship, when at the beginning you are really in love but in the end there isn't much left."
Casillas also hopes to someday return to La Roja, although he recognises his time may have passed by this point.
"I've never said no to Spain and will still fight," he concluded. "I'd still like to [get called up] of course."
