Lewis Hamilton has issued a shock warning that Mercedes will not be in a position to fight for victory over the opening few races of the new F1 season.
Mercedes concluded the opening pre-season test in Barcelona with the leading times as Hamilton finished quickest ahead of new team-mate George Russell.
But the team has struggled over the three days of the second test in Bahrain, with seven-time champion Hamilton now casting doubt on Mercedes' chances of fighting at the front, starting next weekend at the same circuit.
"It's a little bit too early to get into that or have those kinds of thoughts, but at the moment I don't think we'll be competing for wins," said Hamilton.
"There is potential within our car to get us there, we've just got to learn to be able to extract it and fix the problems, which is what we're working on.
"Everyone is doing such an incredible job back at the factory working as hard as they can, but we have some hurdles to overcome.
"Next week we'll get a much better showing of our pace but I think people will be surprised, or least the people who say we keep talking ourselves down. It is a bit different this year."
Porpoising a weakness that masks true potential
Hamilton believes the porpoising phenomenon seen in pre-season testing is a weakness for the Mercedes car and hopes a solution can be found so the most performance can be extracted from the car.
"At the moment that is one of our weaknesses," added Hamilton. "Other people are also experiencing it and it's not great.
"It's definitely a hindrance at the moment but I hope somehow we are able to fix these things so we can realise the true potential of these cars."