Fernando Alonso and Stoffel Vandoorne ended this afternoon's Russian Grand Prix free practice session in 17th and 18th positions respectively. Both drivers spent the day evaluating a suite of component and set-up changes aimed at improving the MCL33's performance and the team's understanding of the car.

For Fernando, today's times were relatively academic: he will be starting towards the back of the grid after receiving grid penalties for fitting new engine components this weekend.

Lando Norris enjoyed his third free practice session of the season behind the wheel, jumping into Fernando's car this morning and completing 25 trouble-free laps. He set a best lap-time of 1m37.022s.

Fernando Alonso: "We knew coming here that this weekend could be quite difficult for us, so today's performance was pretty much expected. That's also why we opted to change the engine components here and take a penalty.

"After Monza and Spa, this track has the highest power sensitivity of the whole season - and we know that's usually a bad sign for our performance. It's something we're trying to understand, so we've been trying different set-ups to reduce the drag on the car.

"Equally, we know we can't perform miracles from one weekend to the next, so it's going to be tough.

"The degradation looks quite high, so we need to choose a good strategy for Sunday: qualifying isn't too meaningful for us this weekend, but I still hope we'll be in the points at the chequered flag.

"A big thanks to Lando for waiting in the pit-lane for 20 minutes for the FP1 green light. I'll have a better starting position on Sunday because of him - so I'm very happy with the job he did today!"

Stoffel Vandoorne: "We've been trying quite a few different things across both cars during practice today - trying to learn about the tyres, which are looking quite interesting. I think everybody has been surprised by just how big the degradation is on the longer runs. Typically, this has been a one-stop race without too much degradation, so the key today was to understand just how the tyres are working.

"I think a two-stopper will still be tricky to make work as overtaking is so difficult around here. But let's see how the degradation pans out - it's usually a little less critical on a Sunday, so probably still a one-stop - but hopefully with the race being a bit more interesting...

"Fernando and I experimented with the tow today: any lap-time we can gain is important, but it's too early to say what we'll do in qualifying tomorrow."

Gil de Ferran, Sporting Director: "For this race weekend, we elected to change power unit components and take a penalty on Fernando's car. One of the knock-ons of that was ensuring Fernando's was the first car out of the pit-lane this morning - correspondingly becoming the first of several cars to earn a penalty, and consequently ensuring he will start ahead of the other penalty-affected drivers. Kudos to everyone in the garage this morning for accomplishing that small but important task.

"The rest of the day's running was primarily focused on race preparation: neither driver encountered any issues throughout the day, which was a positive.

"In FP1 this morning, Lando enjoyed another a smooth and trouble-free session, very quickly getting down to business and immediately setting representative times.

"Clearly, we've got some work to do to improve our competitiveness at a circuit that doesn't seem to suit our car's handling characteristics. We evaluated several new developments and set-up options and made a good start to our weekend."

Check out our Friday gallery from Sochi, here.