The Ghanaian has the worst disciplinary record in La Liga with six yellow cards and one red to his name from 10 games this season.
And ahead of his struggling side's clash at home to Getafe tomorrow, the 22-year-old accused referees of being biased against black players.
Wakaso told the club's website: "I am sorry to say, but referees show cards based on the colour of your skin.
"I think they respect some players and not others.
"Only against Osasuna did we deserve to lose. Every other game was influenced by the referee."
Sergio Garcia and Hector Moreno are both suspended for tomorrow's game so Diego Colotto and Simao are expected to return to the starting line-up.
Getafe have far fewer problems as they sit comfortably in mid-table, but manager Luis Garcia believes it is matches like this one that will decide whether they will remain there or can push on to challenge for a European place.
He told Marca: "I think Espanyol will come out very fired up and we know that in extreme situations people can produce their best.
"After saving the game against Real Valladolid last week we now have to determine whether we're going to be mid-table, higher or lower.
"If we beat Espanyol we will advance positions, but what matters to me is getting 19 points at this stage, with a cup tie to come in December which will also define whether we have a season of excitement or suffering."