The former Real Madrid coach, who played for them and Barcelona as a midfielder during the 1980s spoke ahead of the European showdown at the Bernabeu on Wednesday night as they contest the semi-final, first-leg.
Schalke or Manchester United will meet one of the Spanish giants in the final, but Schuster could not see La Liga's dominance on the continent being broken.
"Right now none of them could compete with Real Madrid or Barcelona as they are the best two teams in Europe," the 51-year-old German told AS.com.
On the game he said there would be "nerves, tension and intensity," as the "Champions League is the title of all titles."
Schuster then explained why Pep Guardiola moved to question the referee ahead of the game against Real Madrid and feels it's because things are not going to plan.
"This is because they have been winning everything over the past years, and now they lost the Copa [del Rey] which is important, but things are not the same."
The former Real Madrid coach couldn't pick a winner though.
"One of these teams will make the final and this is what is important," he said.
