The former Real Madrid player, coach and sporting director believes that Odegaard is a great player, but he has questioned the 22-year-old's mentality.
"Madrid have lost an asset, and an important one at that," Valdano told Onda Cero.
"[Toni] Kroos and [Luka] Modric are getting a lot of minutes with outstanding performances in both cases.
"Madrid are being supported by the entire midfield, because we are forgetting Casemiro, who is already an authority in the team, both football and spiritually speaking.
"And if you're missing Modric and you're missing Kroos one day.... And that's where Isco is, and that's all. Isco is going to be a must with [Fede] Valverde's injury.
"I don't think Odegaard played badly when it was his turn, but he lacked a bit of audacity. He positioned himself too close to Casemiro and he lacked the spotlight to make the final pass, which is what you expect from Odegaard.
"But that has to do with confidence, and I think time would have given him that. But he has lacked patience.
"A Madrid player should be able to [fight for his place] more; he shouldn't give up so soon. And even less so when he is so young and competing for the place of two superstars like Kroos and Modric. Kroos is a superstar and Modric is a superstar. They are not just any two players."