Jofra Archer will be ready for ‘biggest series of our lives’ – Brendon McCullum

England head coach Brendon McCullum has dubbed this winter’s Ashes “the biggest series of our lives”.

It is still two and a half months until his side line up for the first Test in Perth but there is no escaping the importance of a tour that could define the ‘Bazball’ project.

Ordinarily, Sunday’s gargantuan 342-run win over South Africa at the Utilita Bowl would be seen exclusively as a bellwether for England’s white-ball fortunes. But with Australia on the horizon, it is impossible not to look across formats.

Jacob Bethell’s maiden professional century was an important tick in the box for a player who will head Down Under with a realistic hope of making the XI and the dynamic new-ball bowling of Jofra Archer was another step in the right direction.

Archer only returned to the Test arena after four years of injury problems this summer but is seen as a vital weapon in England’s Ashes arsenal. And a devastating opening spell of four wickets for 10 runs against the Proteas showed why he shoulders such expectation.

“That was an unbelievable spell. Huge,” said McCullum.

“(He’s) got quicker. It was box-office bowling… you didn’t want to miss a ball. I thought it was brilliant and not just his pace but his skill, his ability to shift it both ways and to test batters with the steep bounce he gets.

“He’s a proper cricketer, hence why we’ve taken our time with him to make sure that we give him every chance to be in the biggest series of all of our lives. He’s going to be a huge player when we get to Australia, as a number of others are.”

England have rested Ben Duckett and Jamie Smith from this week’s T20 series against South Africa in a bid to keep them fresh for Australia, but have kept Archer involved. Having treated his comeback with kid gloves, McCullum is now keen to keep him simmering.

“It’s always a delicate balance. Sometimes you need to keep bowling and you need to keep ticking over,” he said.

“I think a lot of injuries happen when you almost down tools completely. We’ve had a good plan with Jof over the last little while and he’s rewarded us for the type of planning we’ve had with performances like this one.

“I don’t think we’ll wrap him up per se, we’ll just keep working with him on how he’s going and work out what’s best for him.”

Bethell will also have more chances to build on his breakthrough hundred, including as the country’s youngest ever captain on a T20 trip to Ireland later this month.

Whether he can claim a spot in the team for the first Test is a question McCullum is happy to leave for another day.

“We will work that out when we get to Australia,” he said when asked about his first-choice XI.

“We’ve got a few other fish to fry before we get there. But look, we’ve said about Jacob since we introduced him that he’s got a huge future in front of him. He’s very quickly taken to international cricket and things have come really quickly for him as well.

“I want to celebrate the fact that his first ever professional hundred has been scored in the England jumper at the age of 21. I think David Gower’s the only other (21-year-old to score an England ODI hundred), and he was a pretty good player. We’ll see where Jacob ends up.”

England’s first T20 against South Africa takes place in Cardiff on Wednesday, before the series moves on to Old Trafford and Trent Bridge.