Ferrari ended off the podium and a minute adrift of both Hamilton’s race-winning team-mate Valtteri Bottas at Melbourne, using led the way in which in pre season testing.
However, Sebastian Vettel and Charles Leclerc dominated Friday practice in Bahrain, whereas Mercedes finished more than just half of a second off the pace.
Hamilton said: “The Ferraris have now already been quick from the getgo and picked up more pace from there, therefore that it ’s very different to that which we’ve ever found at Melbourne.
&ldquoWe had some problems with the balance of the vehicle, but we’ve ever made improvements for FP2.
“At the present time it looks like that the Ferraris are ahead, so we need to keep our heads , maintain exercising, examine matters to night and decide to try and keep coming back stronger tomorrow.
“” I presume even once we arrive at qualifying, everything will get just a little bit closer, but it is going to be a difficult struggle. ”
But he admitted it had been “quite tough to figure through where we stand today” and suggested Mercedes was losing some time to Ferrari to the straights.
“it really seems like we do not have the advantage we had in Melbourne and that Ferrari have made a great step forwards,” he explained.
“Through the corners we’ve had a good balance on a single lap and the apex rates look pretty good in comparison with your competitors.
“Ferrari are clearly quick on the straights here however, it may be that they are running their power unit just a little bit harder than we were now. ”
Ancient world championship pioneer Bottas ended fourth-fastest, only over a tenth slower than Hamilton.
“It appears like that ’s going to be quite close between us and Ferrari, they have been clearly faster around here than they were at Melbourne,” he explained.
“So, we’ll have some work to do in order to improve the set-up of our vehicle and that I also provide room for improvement abandoned.
“it appears like it will soon be a tough fight to morrow , which should create qualifying very exciting”
Valtteri Bottas, Mercedes-amg W10