Red Bull Racing says there is no obvious explanation as to why there was such a performance difference between Mark Webber and Sebastian Vettel at the season-opening Australian Grand Prix.
Although the team found a fault with a rear damper after the race, team principal Christian Horner reckoned there was not a single issue that explained why Webber was uncharacteristically so much slower than his team-mate in Australia.
"There were a few issues on the post-mortem that we could see had contributed," explained Horner ahead of the Malaysian Grand Prix.
"I think probably the most telling one was an issue with a rear damper that definitely at some point of the race had happened. We have obviously replaced all the components and I think we have a fairly good understanding as to why, and hopefully he will be back to his usual form this weekend."
He added: "I think that you have a combination of factors. Sebastian was in electrifying form. There was perhaps a set-up direction that Mark went in that was a little bit different to Sebastian, but we are talking minimal differences.
"And then we found this small issue with a rear damper. You try to piece together a puzzle but there is no smoking gun to say, yes: there is the performance difference."
Horner believes that some of the explanation could also well be explained by the fact that Webber has never enjoyed the best of luck as his home race.
"Melbourne has never been a particularly great event for Mark," he said. "He has finished fifth for Minardi, fifth for Williams and fifth for Red Bull. It has almost been like a bogey circuit for him, so he won't be dwelling on Melbourne. He will be very much focused on this weekend and a track that he has always gone well at."
Despite there not being any obvious explanation for Webber's form in the first race, Horner said he is confident that the Australian will be in better form in Sepang.
"Last year the average gap between the two of them was just under two tenths, throughout the season," he said. " We did see some differences, like in Singapore, where that gap was exaggerated.
"But I expect Mark - he has always gone well here, I expect him to be in good form this weekend."