The Blancos hold a four-point lead over the Blaugrana, but could see their advantage dwindle down to a single point with a loss in Saturday's clasico.
However, in an exclusive interview with Goal.com, former Spain striker Alfonso, who played for both Barca and Madrid, revealed the hosts' style has left Jose Mourinho's side with little choice but to adopt an attacking strategy.
"It is very difficult to pick a favorite, but they are two great teams and either side can win. Perhaps Barcelona have home advantage, but Madrid have the edge in the table. I can't call it, but I want Real Madrid to win."
He added, "I think if you want to win at Camp Nou, you have to push them hard because otherwise you will have to wait a long time to see the ball. With Real's physicality and quality, they can do it perfectly.
"Real Madrid have the tougher run-in, but most importantly it's in their hands, regardless of what happens at Camp Nou. They are able to win at any stadium."
The 39-year-old was then questioned whether he believed Pep Guardiola had changed the culture at Barca since his days at the club in the early 2000s, but stated the only differences have been the influx of homegrown players in the first team.
"There has always been this particular touch-based philosophy at Barcelona," he mused.
"Although Guardiola has reinforced the importance of homegrown players in the squad, I think the only difference would be this; that Barcelona look much closer to home.
"However, Barcelona also have a homegrown coach [in Guardiola]. When I was at Barca, I happened to be in a team with many Dutch players, yet you also had [Andres] Iniesta, [Victor] Valdes, Fernando Navarro and Oleguer coming through."
Alfonso then paid tribute to Guardiola, who he feels has successfully translated his finesse on the pitch into becoming an articulate trainer in the dugout.
"[Guardiola] has always been special, both as a human and as a player. He was always so exquisite on the football pitch, and had a magnificent first touch," he continued.
"He has shown his personal traits in his coaching, while maintaining the philosophy of Barca. He is the face of Barcelona.
"Yes, he has been fortunate to be given such an opportunity, but I think he is one of the best coaches in the world."
Follow @GoalUSA on Twitter.
The Morning Email helps you start your workday with everything you need to know: breaking news, entertainment and a dash of fun. Learn more