Ferrari team principal Mattia Binotto has conceded a compromise in engine performance was only a part of the team's issues at the Mexico City Grand Prix.
Carlos Sainz and Charles Leclerc were largely anonymous en route to finishing fifth and sixth as Red Bull and Mercedes outclassed the Scuderia.
Monégaque Leclerc finished 68 seconds behind winner Max Verstappen and lost second in the drivers' championship as a result of Sergio Perez's podium.
Ferrari was understood to have turned down the power output from its engines to protect from reliability issues at the highest altitude cars will race at this year, but Binotto revealed there was more to the team's struggles than that alone.
"In terms of the power unit, we were not at our best performance for the weekend but I don’t think that explains the most," said Binotto.
"That is part of the equation but there is more than that.
“There is certainly more than that and it is something we need to look at and there is not a clear answer right now."
Detailing the issues experienced, Binotto added: “The ride was not great, the balance was not great.
“This is why I think it has to be looked at as we have not [got] a clear explanation.”
Ferrari unaware of how difficult weekend would become
Teams were obliged to participate in the second Pirelli tyre test during FP2 in Mexico, meaning no set-up work could be completed.
Leclerc crashed during that session, further hurting Ferrari's chances, but asked if the team knew how difficult the weekend would be, Binotto replied: "No, I don’t think we knew that it would have been so difficult.
"After FP1 as well, we didn’t realise it. It was only later in the weekend that we found out that the performance was not that great.
“Maybe as well, the FP2 and the tyre testing didn’t help us in order to address the weaknesses and the car set up. But I think that overall, first, we didn’t certainly do a great job and the car on this circuit was not suiting ourselves, but we were not expecting it.
“We were hoping that we could have been certainly a lot better and maybe competitive but it has not been the case.
“Already in Spa it was very similar where we have been very slow and it was somehow outstanding in terms of bad pace, and the same here as well, very similar. It is something we need to look at and try to react to for the last two races.”