England’s white-ball coach, Brendon McCullum, was full of praise for the captain, Harry Brook, after Saturday’s eight-wicket victory over Sri Lanka completed a T20 series whitewash and took the side to No 1 in the world.

Brook, player of the T20 series against Sri Lanka, has now won 23 of his 26 completed games as captain. If he is not yet considered a suitable candidate as Test leader, the cap fits nicely in the smash ’n’ grab format.

“He’s grown not just as captain, but as a person as well,” said McCullum. “He seems very comfortable now as a leader of this side and the guys follow him, they trust him. Obviously his batting’s been on a different planet when it comes to T20 cricket, but I think his ability to do things differently based on what’s required with the conditions, and also against the opposition, has been probably the most impressive element.”

“Twenty20 is such an inconsistent game, so you can never take your eye off what you’re trying to achieve, but over the last 18 months or so we’ve found a nice level of consistency. We are not the finished article as yet, but the work we’ve done on the environment and the setup, and the depth that we’ve got in our side now is certainly encouraging.”

Alongside his relationship with Brook, there is a new guy in town to manage – McCullum’s old buddy and the new Test coach, Stephen Fleming, who was also at Old Trafford on Saturday.

“Flem and I are great mates,” said McCullum. “He was my captain coming through and the great thing about him is he always made you feel like his equal. Our relationship is brilliant and fundamentally we both just want what is right for English cricket and will do whatever we can across the formats to make cricket as good as we can in the time that we’re here. I think our relationship is a real strength, we talk regularly regardless of these jobs.”

And he was confident that their relationship would ensure there was no conflict when there is a clash between Test cricket and white ball commitments. McCullum even drew Fleming into the England huddle before Saturday’s game.

“He was a bit reluctant but it’s brilliant to have him around. He’s one of the most successful T20 coaches in the world, so it is quite handy to have him run his eye over the environment.”

England begin a three-match ODI series against Sri Lanka on Tuesday. McCullum had warm words about Sonny Baker, whose control and pace has been a revelation. “He bowls 90mph, has a good slower ball, can swing the ball both ways and is an incredible competitor. He has been tested in international cricket and probably didn’t get the instant results he wanted but he’ll be walking a foot taller now and that’s great for all of us whether that’s T20 cricket, one-day cricket, or Test cricket. People like him are rare commodities.”

Towards the other end of his England career is Adil Rashid, who will be 40 by the time the next T20 World Cup comes around.

“We hope Rash is around for a long time. He’s a world-class performer but we do have to have plans in place. We have guys we are keeping an eye on consistently, obviously Rehan Ahmed has been around our squad a lot and he’s never let us down, there are lots of other guys out there as well. The one-dayers could be an opportunity to have a look.”