The Spaniard labelled his AMR23 as "undriveable" after the race at the Marina Bay circuit last weekend, as he struggled to find any performance throughout Sunday's grand prix.
It was only after the grand prix, however, that Aston Martin realised the extent to which Alonso's performance had been hit by a damaged front suspension shroud, which had come loose on lap two and rotated side-on to disturb the car's aerodynamics.
Speaking ahead of the Japanese Grand Prix, Alonso did not offer any specific details about how much lap time the problem cost him, but said it explained why things looked so bad.
"Definitely it was not helping," said the Spaniard. "We know how much it affected [us], and we will not share, but it was significant.
"So I'm a little bit less worried about the performance in Singapore after knowing the damage that we had.
"The pace was not the real one in the race and, without that, maybe we could have followed the train of the leaders and have less problems with the Alpine and then with [Sergio] Perez. Then everything would be changed after.
"When you're not too fast, you get into a lot of problems."
While one possibility for the cause of the suspension problem was Alonso running over debris from Yuki Tsunoda's opening lap clash with Perez, Alonso would not reveal exactly what happened.
"It is a private thing," he said.
Source: Autosport