Haas team principal Guenther Steiner has explained what happened to cause its both its cars to retire from the 2018 Formula 1 opener in Australia and how it plans to bounce back.

The US squad suffered a double disaster during the Melbourne race while both Kevin Magnussen and Romain Grosjean were running inside the top five. Magnussen was the first to pit for Haas due to track position but was forced to stop at turn 4 with a loose left rear wheel before Grosjean suffered a near-identical fate two laps later with a loose front left tyre.

Steiner confirmed both the wheel nuts on both cars were cross-threaded meaning neither was properly fitted which forced the on-track stops.

The Haas team boss puts the mistakes down to human error and a lack of pit stop practice in Australia rather than procedural problems and called it “unbelievable” as the team had completed hundreds of practice stops during the winter and in testing only to suffer two problems during the 2018 F1 opening race.

“We had two failures on the pit stops – didn’t tie the wheels on correctly – so we had to stop the cars,” Steiner said. “As much as you don’t want to say it, it’s racing. It happens even though it shouldn’t.

“It’s almost unbelievable to have this in one race, and on two cars, while running fourth and fifth. It’s very disappointing.”

Steiner says his team will aim to rectify the issue and has thrown his support behind his pit crew, as Haas garage members looked visibly distraught after the failures in Australia, and is certain the issues won’t crop up in future races.

The Haas team chief says he can take comfort from the squad’s track performance having headed up the midfield while also getting in front of both the Red Bull cars before the pit stop disasters.

“The good thing we can take away from this is that the car is competitive,” he said. “We just need to get our heads up again, to get well prepared for Bahrain. We’ll focus on that one and get our pit stops sorted out.”

Haas were fined €10,000 (€5,000 per car) for the unsafe pit release with the penalty noting “the team ordered the car to stop immediately”.