Wolff knows about midfield "surprises" in 2019

Mercedes boss Toto Wolff has admitted he is wary of some of the surprise packages emerging from the "midfield" this season in Formula 1.

Mercedes cruised to another championship last season, with Ferrari and Red Bull behind them - but Renault, the nearest team to Red Bull, were over 500 points adrift of the energy drink-brand team.

Only one driver (Sergio Perez of Force India) outside of the top three managed to finish on the podium, but the Mercedes boss believes 2019 will see a closer season in F1.

"I see everybody," Wolff said when asked about Mercedes' potential rivals. "There could be Red Bull, for sure. It has the resource to be competitive, and it has always been a flexible team to adapt to new regulations, and even change directions.

"Ferrari has just got stronger and stronger and stronger. Then, Renault was the quickest team on the last few days. Toro Rosso was unbelievable, Alfa Romeo was (also) very good.

"So all of them; there could be a situation where we are all very close together and there could be surprises."

Last season, Ferrari had the quicker power unit for the first half of the season, and it looked as if Sebastian Vettel would take Lewis Hamilton all the way but a drop off from the German, as well as his team, saw the Silver Arrows continue their dominance of modern Formula One.