Referring to Mercedes, he told the Austrian newspaper Kurier that the Ross Brawn-led team seems to have come up with "very good improvements" and "a major development".
He is believed to be referring to clever new systems on the W03, with the latest discovery said to boost top speed significantly by combining 'DRS' with a new and legal F-duct solution.
Red Bull's Dr Helmut Marko agrees that the Mercedes idea is "shrewd", adding that there is not time to fit a similar system to the RB8 before Melbourne.
"Mercedes is the big question mark -- I think they are also really fast."
Finally realising Mercedes' apparent speed, a newspaper recently crowned the Brackley based team the 'Bluff champion' of the 2012 winter.
Mercedes is the big question mark -- I think they are also really fast
Michael Schumacher, however, insists it has not been a deliberate strategy.
"Formula one is just so complex that we simply don't know much about how the other teams are going. Clearly, the W03 is a step forward," he told Bild-Zeitung.
"The question is how big our step has been compared to the others. We really need to wait until the first race."