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.
No disappointment in project
Alonso's struggles at the Singapore GP, where he eventually finished 15th, come in the wake of an equally difficult time at the Italian GP where he ended up ninth.
Those results are a far cry from the form that Alonso and Aston Martin showed at the start of the season when it began the campaign as Red Bull's main challenger.
But despite having had just one podium finish since the Canadian GP, with a second place in the Netherlands, Alonso is clear there is no sense of frustration or disappointment about the place Aston Martin finds itself in right now.
"Not at all," he said. "I'm extremely happy with the project.
"Also in difficult races like Singapore or Monza, all our debriefs, all our meetings with the factory, they are very productive. It is the weekends that we learn more in the season.
"So the steps that we plan ahead for the future, or for next year when we come to those races, are just huge.
"I never saw that kind of scale in terms of ideas and things on the table. So the motivation that the team has to become a top team and the resources and the determination is just outstanding. I'm very happy."
He added: "We have to accept that everyone here [in F1] has a very high level. Everyone has great designers, great team, wind tunnels, all these kinds of things.
"When we think about our wind tunnel that will be built next year, and we have high hopes, most of the top teams, they have that wind tunnel already for a few years. So we will just level their capacity.
"We are just now down. This is something that we need to have our feet on the ground [for] as well."
