Honda is to investigate the MGU-H problem which resulted in Pierre Gasly having to retire from the Australian GP.

After a winter that showed promise with strong reliability, the reality was a little less rosy with Toro Rosso left battling with Williams and Sauber towards the back of the grid as the performance continues to lag behind their fellow engine suppliers.

During the race, echoes of the past then returned with Gasly having to return to the pits after a puff of smoke was seen coming from the back of his car and later confirmed to be a problem with the hybrid system.

"After Turn 12 the engine just switched off, it came back on again but I was really slow and I couldn’t upshift," the Frenchman explained.

"For sure I’m not going to lie it’s a pain in the ass to have it, but that’s how it is and everyone will try to make it as close as possible for the next races."

With only three MGU-H's allowed for the entire season, it raises immediate concerns that any further problems could lead to penalties sooner than hoped and that particularly frustrates Gasly after the hope raised in testing.

"I think the regulation is tough for everyone. Testing went so well with no issues at all, it was looking very good. [It’s] just a shame to face it now. I would rather have it [happen] at the last day of testing and come here with no issues.

"For sure it’s not going to be easy, it means probably at some point we’ll have penalties, but I don’t really want to think about it now I want to think about the next race and have a good race weekend."

Honda F1 chief Toyoharu Tanabe expressed "disappointment" at the first physical failure of one of the Japanese manufacturer's units this year and revealed the next step.

"We now have to investigate the precise cause and then we have a few days of hard work to ensure we do not have a repeat of the problem at the next race."