Singapore Grand Prix: Five things to watch at for

Five talking points ahead of this weekend's Singapore Grand Prix, Round 15 of the 2016 Formula 1 World Championship, at Marina Bay Circuit.

Formula One may be undergoing a multi-billion dollar buy-out, but expect more questions than answers as teams and drivers absorb last week's deal. Bernie Ecclestone, who has run F1 for the best part of 40 years, will not even be around to discuss the sale to US billionaire John Malone's Liberty Media group, opting to skip Singapore and stay in London instead.

21st Century Fox vice-chairman Chase Carey, who will become F1's new chairman working alongside Ecclestone, has promised not to "Americanise" a sport which has strong European traditions. But changes are afoot. Ecclestone and Carey are thought to be working towards a 25-race calendar -- expanded from a record 21 GPs this year -- while Liberty Media will bring some much overdue social media and interactive savvy to a sport whose traditional fanbase faces erosion.

The mosquito-borne disease caused concern ahead of the Rio Olympics and Formula One teams will be on their guard after Singapore was hit by one of the worst outbreaks outside of South America. Several countries including Taiwan and Australia have warned pregnant women against visiting Singapore because of Zika, which is sexually transmissible and can cause babies to be born with abnormally small heads.

Nico Rosberg has consulted Mercedes team doctors and other drivers with young families have also expressed reservations, according to reports. Singapore is not alone, with races still to come in nearby Kuala Lumpur, Mexico and Brazil where there have also been Zika outbreaks. FIA doctors have been advising teams and, despite the extreme heat, long sleeves will be the order of the day for pit lane crews -- along with the liberal use of mosquito repellent.

Red Bull's teenage sensation Max Verstappen got a finger-wagging warning from FIA race director Charlie Whiting after his wheel-to-wheel battles bordered on the dangerous in Belgium three weeks ago. But the 18-year-old showed a cooler head in Monza and now believes a second victory of his fledgling career is possible in Singapore.

The winding street circuit should favour the Red Bulls of Verstappen and Daniel Ricciardo with their downforce advantage over the powerful and slick Mercedes. Not only that, an engine upgrade from Renault is due to arrive this week which should give them a power-unit boost. "Singapore is definitely one of my favourites," Verstappen said. "It's very challenging, not easy to understand and also the heat makes it even harder."

Sebastian Vettel gave Ferrari their most recent win in Singapore a year ago as Mercedes suffered a mysterious performance meltdown in the hot and humid tropical night race. Ferrari are gambling all out for a repeat victory by opting for the maximum allowed nine sets of the stickiest ultrasoft tyres for each of their drivers.

The 23-turn street circuit places a premium on downforce and mechanical grip, compromising runaway championship leader Mercedes' power and aerodynamic advantage, and giving Ferrari and Red Bull a chance to challenge. It's an aggressive and risky move -- Mercedes and Red Bull are taking seven sets of ultrasofts to spread their strategy options -- but team boss Maurizio Arrivabene thinks it is worth a shot. "Our best chances I see as Singapore, Suzuka and Austin," he said.

Organisers have vowed that security this year will be tighter than ever after a spectator climbed through a gap in a fence and walked onto the circuit mid-race, startling race-leader Sebastian Vettel. "There's a man on the track!" Vettel yelled over the team radio as he hurtled past the intruder at 280 kilometres (174 miles) per hour.

The organisers promised to "fortify the infrastructure and manpower" following an investigation into the incident. The British invader was sentenced to six weeks in prison for "endangering the lives of drivers".