Real will be at Anfield for the second-leg of their Champions League quarterfinal tie defending a 3-1 lead.
Ayestaran, who was working for Liverpool when they won the Champions League in 2005, thinks the absence of supporters at Anfield will give Madrid a massive boost.
“Real Madrid gain a lot when Anfield is empty," he told MARCA.
“The atmosphere I experienced in the quarter-finals with Juve and in the semi-finals with Chelsea, wow, that's heavy. It pushes your team a lot.
“That game at Anfield is not easy. But Madrid have got a lot of courage from experiencing that kind of atmosphere with top players. But now they win.
“Now they have positive momentum. They have players in midfield like Casemiro, Kroos and Modric who are at the level expected of them. And that means that any element that comes into the team can do well.
“They (Liverpool) are at the opposite point, with a lot of doubts throughout the year. The absentees give them a sea of doubts."