Argentina striker Gonzalo Higuain was ruled out for up to four months after having back surgery in the United States on Tuesday, and Jose Mourinho's only recognised alternative at centre forward is the inconsistent Karim Benzema.
"We are scanning the market after the uncertainty over Higuain was resolved," Valdano said.
"We'll see if we can find a player who can help us for six months. We are being linked with a lot of names but it best not to go into details, but it is true we are looking for a number nine."
Local media have linked the club with Bayern Munich's Miroslav Klose and Manchester City's Emmanuel Adebayour among others.
Mourinho was keen to point out he was not unhappy with France international Benzema, who has only managed one goal in La Liga this season.
"We don't want a striker because we don't like Karim," the Portuguese said after his side's 3-1 King's Cup quarter-final first leg win over Atletico Madrid.
"Karim is working harder than ever, especially on his defensive duties. He isn't selfish and he helps the team. It's just he lacks a hunger for goals.
"Cristiano Ronaldo has hunger. Benzema is a great player. When Valdano says they will try to sign a striker it's because we only have Karim and we don't have an alternative."
Real came back to beat Atletico at the Bernabeu with goals from Sergio Ramos, Ronaldo and Mesut Ozil. Benzema was substituted in the second half.
