Stake F1 Team KICK Sauber returned to action after the summer break with two sessions of practice for the Dutch Grand Prix.

Rain affected the first of the two, while sun shone over the second - but both featured strong, gusty winds that created difficult conditions for the drivers.

Rookie Robert Shwartzman did a fine job in FP1, standing in for Valtteri Bottas, who returned for FP2: while Zhou Guanyu completed both sessions in a productive fashion as the team worked to set up the cars for the rest of the weekend ahead.

Valtteri Bottas: "Coming back to the car after a few weeks off and finding these blustery conditions was definitely tricky! It was not easy to find the right balance today and, with the conditions changing so quickly, it was difficult to find the rhythm you needed to get into the flow, especially on such a track. However, we have one more practice session tomorrow on top of the work we are going to do tonight: our job will be to find a bit more stability, and that will translate into more performance. We know we are still lacking something in terms of pace to be in the top ten, but tomorrow the conditions will be difficult again and, together with some luck, that could help us. For now, we need to focus on doing our part to get a better overall balance."

Zhou Guanyu: "It feels great to be back on track - and Zandvoort always brings good energy. Today was quite a smooth day for us overall: the track and wind conditions were quite challenging, but we still managed to complete two clean sessions that allowed us to collect valuable data and information. It looks like we are not too far off, but we still need to find more pace, especially on high fuel. As in previous races, we've seen that our chances are better when conditions are mixed compared to a fully dry track. With some rain and wind likely tomorrow, we're hopeful for a good day that will allow us to seize our opportunities, putting us in a good position for Sunday's race."

Robert Shwartzman: "First of all, I would like to thank Stake F1 Team KICK Sauber and Ferrari for this opportunity. The team was super welcoming to me right away, and I also got to see some familiar faces as well, people I worked with at Ferrari before. It had been nearly a year since I last drove a Formula One car, back in Abu Dhabi, and once I got here, I knew I had to adapt quickly. On top of it, Zandvoort is possibly one of the most challenging racetracks, although a very enjoyable one to drive, and with today's mixed conditions I needed to be on it straight away. Overall, I can say I am happy with today's performance: it's been a good learning session despite the rain and strong winds, and the car felt good. I got stuck in some traffic towards the end, which made me lose some time and made it difficult to put in a better laptime - I think I could have improved even further on the slicks had we had one extra lap. Still, it's been a good day, and I am happy with how things have gone."

Check out our Friday gallery from Zandvoort here.