Although he ended the final test day in second place three tenths off Sergio Perez, it was not an easy final session for Lewis Hamilton.
The Mercedes W14 was very twitchy on the exit of corners during his timed lap runs, as he struggled to match the pace of Red Bull and Ferrari on the harder compound tyres.
He eventually found pace on the softer C3 and C4 compounds to go second quickest, but despite being initially upbeat Hamilton admitted that some of the "balance limitations" from the W13 are still present in their 2023 challenger.
"Some of the balance limitations that we had last year are just present, so we've been working through them," he said to media, including RacingNews365.com.
"I'm really proud of everyone in the team for continuing to remain positive after a tough year, last year, and the amazing work through winter for us to arrive and have the mileage that we've had."
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Hamilton: We've had a couple of difficult days
Mercedes was seen holding a meeting late into the evening after the second test day was complete, after what they described was "struggle with the car balance" throughout the day.
Hamilton made it no secret that the team suffered from a "difficult" day, but admits that there are still some "underlying things" they are working on.
He added: "I think we've had a couple of difficult days. And yesterday particularly was difficult, the first day didn't feel too bad. Yesterday was a little bit more of a struggle.
"The bouncing that we had has pretty much gone, so that's a that's a huge step for us.
"But there are still some underlying things that we're working through."
Ahead of the 2023 F1 season, RacingNews365.com journalists Dieter Rencken and Michael Butterworth look back on a winter break laden with intrigue and controversy.