Bahrain preview - cause for concern at Mercedes?

Was race strategy the only reason Mercedes were able to beat Ferrari in the Australian season opener? Did the Scuderia drop the ball? And if so, do they have the pace to not only worry, but more importantly beat, the Silver Arrows? We may get our answers this weekend...

Bahrain, of course, was one of Ferrari's stronger races last year, particularly as Mercedes suffered with brake-by-wire problems. Lewis Hamilton clung on to victory, but Kimi Raikkonen had been closing fast - and was just three seconds back - at the flag. Mercedes aren't ignoring the warning.

"Bahrain is a track that should suit Ferrari, so we expect even smaller gaps and a very close match this weekend," Mercedes boss Toto Wolff admits.

"We've stepped up our game once again with a fantastic car," points leader Nico Rosberg says. "But Ferrari were a real threat all weekend in Melbourne and it's clear that we've got a big battle on our hands, so we have to keep pushing very hard.

"I've had some great battles in Bahrain in the last two years with Lewis and also the Ferraris, so I'm expecting more of the same this time and very much looking forward to that. It was great to win the first race - but the aim is to come out on top at every step of the way this season, starting this weekend."

Starts a concern for Mercedes

After tardy getaways put both Rosberg and Hamilton on the back foot in Australia, it is perhaps no surprise that both men have been looking at ways to improve for Bahrain.

Hamilton, who has won the race for the last two years running, remains upbeat about his chances despite seeing his team mate take the championship lead for the first time since September 2014 in round one.

"I have a good feeling about my pace," Hamilton says. "I was ahead all weekend [in Australia] until the race start last time out, so I'm confident heading to Bahrain. It's been entertaining on track for the past two seasons there, so more of the same would be great!"

Ferrari riding high after opening weekend

Over at Ferrari, meanwhile, confidence and optimism is high after a very promising opening weekend, which included the Scuderia taking an early one-two and looking well set for victory right up until the mid-race stoppage.

"I think we managed to close the gap more than anyone else so there are plenty of positives," Sebastian Vettel reflected.

"At home in Maranello there has been a lot of work going into this car and I think this is the right car that should allow us to put a lot of pressure on these guys. We know that the benchmark is high but as I said, we are on the right track, things are coming together."

Alonso ruled out

Fernando Alonso will be forced to miss this weekend's race on medical advice, after doctors decided he had not recovered sufficiently from the injuries he suffered in his frightening crash in Australia.

The Spaniard, who will still be present all weekend after pledging to support the team and his replacement Stoffel Vandoorne in any way he can, revealed he suffered fractured ribs and a collapsed lung in the crash.

He will be assessed again before China to establish whether he is fit enough to return.

Vandoorne has previous form in Sakhir - from six GP2 races at the Bahrain International Circuit he has an enviable record of three wins and five podiums.

Midfield almost too close to call

Before the season, Williams had hoped to offer a challenge to Ferrari - and also to stay ahead of Red Bull. Such ambitions didn't quite materialise in Australia, but the team have reason to be optimistic of a stronger weekend at the Bahrain International Circuit, a bona fide horsepower track.

And while that might also work against Red Bull - Renault have certainly improved this year, but still carry a deficit - their sister team Toro Rosso have a very different concern as they look to avoid the snags that consigned them to ninth and tenth in Melbourne. Despite their late switch to Ferrari power, the team appear to have a superb car capable of running very close to the front - and are under pressure to capitalise as a result.

Force India and McLaren are also firmly in the mix, the latter's enhanced MP4-31 proving a far more competitive proposition than the team's 2015 car.

Qualifying in Australia proved just how close the fight is - less than one second covered Max Verstappen in fifth down to Jenson Button in 12th, meaning the smallest of margins - or mistakes - can be decisive.

WATCH: Your guide to the Bahrain Grand Prix

Qualifying unchanged, tyres could again be pivotal

The new elimination-style qualifying system continues this weekend after its controversial debut in Australia.

This will perhaps be a truer test: with the experience of Australia to draw on, teams and drivers will be more prepared for the rolling 90-second eliminations - although whether that leads to a Q3 climax remains to be seen.

While there could still be some surprises therefore, the new three-compound tyre selection could be even more of a factor. Pirelli have brought the same compound choices as Australia - the mediums, softs and supersofts - and Hamilton and Rosberg have gone for a set of mediums each, then six sets of softs and six of supersofts. The Ferrari drivers, however, have gone for three sets of mediums, four softs and six supersofts, while the Williams duo's figures are three, three and seven and Red Bull's two, five and six. Such differences are very intriguing, and could set up a fantastic race of differing strategies.

The granite-based asphalt surface at Sakhir is rough and abrasive, which increases tyre wear, and the track is rear-limited thanks to the number of slow corners where good traction is crucial.

"The new tyre regulations for 2016 proved to be a big success," says Pirelli motorsport director Paul Hembery, "providing many different strategy options and talking points for all the teams in Australia. Bahrain is a very different type of circuit, with tyre behaviour affected by a big drop in temperature as the race goes on. This provides a different set of challenges and parameters, so it will be interesting to see who has learned most from Australia in order to take best advantage of another new situation. The quite diverse choices from the teams will play a key role in the race outcome."

The forecast

Although the weather has been surprisingly inclement in the build-up to the Grand Prix - rain and dark clouds settled overhead on Thursday - it is expected to improve over the weekend. The sun is forecast to return on Friday, with ambient temperatures slightly cooler than last year at 23 degrees Celsius - which is expected to rise to 25 on Saturday and 26 on Sunday.

The race itself will start at 1800 local time (1500 GMT), and will run over 57 laps or 308.238 kilometres (191.533 miles).