Lewis Hamilton says Mercedes made improvements on the final day of pre-season testing in Bahrain but admits the Brackley squad didn't conclude its weekend where it wanted to be.
Hamilton ended the day P5 in the pecking order, with 54 laps on the board but over a second behind Red Bull pace-setter Max Verstappen.
Both Hamilton and teammate Valtteri Bottas admitted to struggling over the weekend with the temperamental rear end of Mercedes' W12, something that was visually clear from the outset at Sakhir.
But the seven-time world champion said the team just put its head down and worked methodically to improve its 2021 contender, with no real concern for its relative performance or the speed of its rivals.
"I've never been a massive fan of testing, I just love racing!" said Hamilton after Sunday's final session.
"It's probably the only year I would have asked for more days though, because we've got lots of work to do.
©Mercedes
"We've never felt in the past that we were quicker than everyone else after testing because you never know what people are doing with the fuel and set-ups.
"We always just focus on understanding our car the best way we can so if I'm honest, I feel the same this year. We won't know until we get to qualifying in two weeks' time exactly where we stand.
"Today we made some improvements but it's still not where we want to be. I can't pick out any one area, it just feels globally through the lap that we need to improve.
"I'm looking forward to getting back into competition and back in that focus mode. Our team is all rowing in the same boat - we win and we lose together.
"I'm just happy to start another journey together with these boys and girls."
Mercedes trackside engineering director Andrew Shovlin confirmed that the team had made progress in improving the balance of its W12, but the Briton also acknowledged that on race pace, Mercedes was not as quick as Red Bull.
"We've made a bit of progress with the balance on higher fuel and the car was more predictable but we can see from the data we've collected over the last few days that on race pace, we're not as quick as Red Bull," he said.
"The lower fuel work was a more confusing picture, we didn't gain enough and we need to go and look at our approach as far too many cars were ahead of us on pace today.
"We've had issues in recent years with pace in winter testing and managed to make good progress before the first race but we may have our work cut out this time.
"We've not got long before we're back here for the race so we've planned a programme of work to try and understand some of our issues and will be leaving no stone unturned in our efforts to find some more speed over the next ten days."
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