Valdano insists Mourinho has achieved nothing special at Real.
"Since Di Stefano's era, Real Madrid have won more titles than all the other Spanish teams together," Valdano told Fox Sports.
"That means the team wins a title every two years. Mourinho is within the average - he has taken two years and has won a title.
"Tactical technicians are gaining importance in football. Mourinho is associated with the word victory. He has won seven league titles in 10 years and the desperation to win remains with him.
"It's why people like him will always have [a] market. He's a safe bet."