The striker was heavily linked with a move to Real in the summer, before Los Blancos opted to sign Mariano Diaz as a replacement for departed superstar Cristiano Ronaldo.
Aspas has since scored eight goals in 11 La Liga games, while Mariano has scored just once in all competitions in the same number of games.
That has led to suggestions that Aspas should be a priority target for Real in the winter transfer window.
The former Liverpool forward has, however, insisted that he is in no hurry to leave Celta.
"Iago Aspas is very quiet in Celta, I have many years left on my contract, and if they want me first they have to agree with the club," he told Marca.
"After that I cannot do anything."
Real sacked Julen Lopetegui after a terrible start to the season, and they remain sixth in La Liga, seven points behind leaders Barcelona, who beat them 5-1 in Lopetegui's last game in charge.
Aspas, though, believes that they have merely failed to replace Ronaldo, who would regularly bail out the Spanish giants before his move to Juventus.
"They have good players," Aspas added. "It's true that sometimes they did not play well, they changed their game model from last year, and they have not had time.
"But so many defeats are hard, and more so in Madrid.
"They also had the loss of Cristiano. He gave them 40 or 50 goals, every year. Before you had a bad game and he solved it. It is impossible not to notice it."