Real Madrid should have signed a new striker in January because Karim Benzema "doesn't even look dangerous", according to Jean-Pierre Papin.
Benzema has scored just two goals in La Liga this season and has only played the full 90 minutes in five of his 15 top-flight appearances this term.
It has been suggested Madrid will invest heavily in attackers during the close-season, with Robert Lewandowski and Mauro Icardi believed to be their top targets.
But Papin, the Ballon d'Or winner in 1991, believes they should have dipped into the market in January to correct problems that have seen them fall 19 points adrift of LaLiga leaders Barcelona.
"Personally, I would have signed a number nine, but that's my point of few. I think Madrid needed to strengthen what they've got there," Papin told AS.
"The perfect example is Benzema - he scored a lot of goals and now nothing's coming off for him. He doesn't even look dangerous, which is very strange.
"But nobody is better placed than [Zinedine] Zidane to judge what the team needs. He knows the group and has confidence in those players.
"He wasn't wrong over the last two seasons so we have to trust him. I respect Zidane a lot. What he has done is great."
Of Benzema's difficulties in front of goal, he added: "The life of a striker is not perfect all the time, there's always a period when things don't happen for you.
"The problem is that it's happening for Madrid collectively all at the same time. I think Madrid will be stronger in the coming weeks."
Cristiano Ronaldo is also enduring a tough season, with 10 players scoring more than his eight La Liga goals this season. However, he leads the way in the Champions League, having hit the back of the net nine times.
Papin does not think the five-time Ballon d'Or winner is past his best, stating matters behind the scenes have likely led to a dip in his form.
He said: "There are a lot of rumours about his possible departure from the club in the summer, which won't help his confidence. He needs to play and score to be one hundred per cent.
"He is 33 years old. I don't think he's in decline, but there are players alongside him who aren't playing as well as they have.
"Benzema does not score and Cristiano finding it difficult are factors that demonstrate things are not well for Madrid."