Valtteri ended Friday in Baku second quickest, just 0.100s shy of Max Verstappen's pace-setting Red Bull, but there is still more work to do for the Silver Arrows ahead of Qualifying for the Azerbaijan Grand Prix.
Valtteri: Practice one was quite tricky
"Practice one was quite tricky: we were struggling with the setup of the car and it wasn't so well balanced," said Valtteri. "Today, we needed multiple laps in a row to generate the temperatures we want for a good balance.
"FP1 wasn't a happy session, but we made some changes ahead of FP2 and the car definitely felt more comfortable. We are moving in the right direction and hopefully we'll make another step this evening. We'll work hard and if we can find those gains we'll be right up there fighting for pole position."
Lewis: It was a difficult day out there
After lapping fifth in the morning, Lewis could only manage P10 in the afternoon, on a scrappy day when finding a rhythm was tough as yellow flag followed yellow flag.
"It was a difficult day out there," said Lewis. "This circuit is a tough one and we had a few challenges that we tried to work through today.
"We've clearly still got lots of work to do ahead of qualifying, but Valtteri's time in FP2 looked promising, so there is obviously pace in the car, which is encouraging. Now it's just a case of getting our heads together tonight to work out exactly how to extract that pace across the entire weekend."
James: We have work to do overnight
After a tricky day of stop-start action, Mercedes-AMG Petronas Motorsport Technical Director James Allison is expecting to see the pace ramp up on Saturday.
"It was a scrappy day punctuated every few seconds by dozens and dozens of off-track frolics," said James. "The associated yellow flags interrupted the rhythm at a circuit where it is quite challenging to get temperature into the tyres, especially the fronts, and that as much as anything dictated your position on the leader board today.
"However, we have work to do overnight to make the car's handling sweeter, as both drivers were struggling to get temperature into the front tyres and, as a consequence, suffering with front locking. There is going to be a lot more lap time to come from all of the front runners as the track rubbers in and the drivers gain in confidence.
"It's already close at the front, so I expect that those who work well overnight, and keep a cool head tomorrow, will be rewarded in qualifying and the race."