The ex-Madrid official believes the former Porto, Chelsea and Inter boss should know how to act better, while praising Barcelona's signing of Sanchez from Udinese
The Portuguese tactician took part in the fracas in the closing stages of Barcelona's 3-2 win at the Camp Nou, pushing his finger into the eye of Barcelona assistant coach Tito Vilanova.
Mourinho has been the subject of intense scrutiny for his actions in Wednesday's contest, and Valdano, who does not see eye to eye with the Portuguese, has criticised the coach's behaviour.
"Let's say that what happened does not exactly honour Real Madrid or Mourinho. I am convinced no-one is proud about what happened," Valdano told ADN Deportes.
"Mourinho came to a club with 109 years of history and of course he represents a club with a very solid culture. What happened is that in these moments the tension between Real Madrid and Barcelona is so high that everyone is overcome by the pressure."
Valdano admitted that Barcelona did a good work by signing Alexis Sanchez as he thinks the Chilean 'will fit in perfectly'.
"He is very fast, he also recovers balls with such ease that it is not normal for a player like him and he demonstrated in the first match, practically without having trained with his teammates, that he can unbalance things, which will be very important for Barca," Valdano added.
"I think Cesc Fabregas' arrival will be very important for Alexis, just like it will be for Lionel Messi."