Real Madrid go head to head with Barcelona at the Nou Camp looking to close the 11-point gap on their Catalan rivals.
Barcelona are sitting pretty at the top of La Liga, while Atletico lie second, six points adrift of Barca and five ahead of Real.
Atletico suffered a shock defeat to Espanyol last night as Sergio Garcia scored a late winner.
With Diego Simeone’s side hopeful of keeping pace with Barca, Forlan admits even he wants rivals Real to inflict defeat on Ernesto Valverde’s side this afternoon.
“Hopefully Real Madrid win El Clasico as this would help Atletico move closer to the top of the table,” Forlan told Cadena Cope.
Forlan scored 74 goals in 134 league appearances for Atletico during his playing days and admits he would like to return one day.
“My intention is to someday return to Atletico with a future project; that would be a dream for me,” he added.
Currently leading the line for Atletico is Antoine Griezmann, although his future remains unclear in the summer.
Manchester United and Barcelona are both keen on signing the Frenchman, but Forlan hopes he stays at the Wanda Metropolitano for another season.
“Griezmann’s future? No Atleti fan wants him to leave, and I am no different!” he added.
Griezmann is under contract with the Madrid outfit until 2022.