Senior England player Jos Buttler on Tuesday backed under-fire Brendon McCullum, saying the New Zealander was "as sharp a coach as I've ever worked with".
McCullum is desperate for success at the T20 World Cup in India, where England face the West Indies in Mumbai on Wednesday, after facing flak for the torrid 4-1 thumping in the Ashes.
England coach McCullum was accused of being too laid-back and allowing a drinking culture in the camp.
White-ball captain Harry Brook had to apologise after being involved in an altercation with a night-club bouncer on the eve-of-Ashes tour of New Zealand.
On Sunday, McCullum was seen sending messages via walkie-talkie to the England players during drinks breaks as they squeezed home against Nepal in a last-ball nail-biter in Mumbai.
It appeared to be part of a more hands-on, proactive coaching approach, and Buttler welcomed it.
"I think he's had those walkie-talkies for a while now, but then communication from top to bottom has always been really good in the group," former captain Buttler told reporters at the Wankhede stadium ahead of training.
"'Baz' can sit with his feet up and his sunglasses on and look very relaxed.
"But he's as sharp a coach as I've ever worked with. He doesn't miss a beat.
"He was a successful captain, so he's got lots of great messages, knowledge and stuff to pass on to all the players.
"His relationship with Harry Brook has been a great one for this team. They're really close."
Brook took over after Buttler stood down as captain last year, following England's group stage exit from the 50-over Champions Trophy in Pakistan and the UAE.
That followed an embarrassing title defence at the 50-over World Cup in India in 2023 and a semifinal exit as defending champions at the 2024 T20 World Cup in the Caribbean.
Buttler, who led England T20 World Cup glory in 2022 in Australia, said it had been tricky to adjust to just being a player again after being captain.
In his second game after giving up the role, he sought advice from Joe Root, who had stood down as test captain but played on under Ben Stokes.
"He was stood at slip and I was keeping wicket. We had five or 10 minutes just talking about it," he said.
"How different it is when he's been captain... and some of the various emotions he felt, the challenges that he found, and yes it was really helpful."
England on Tuesday announced one change from the team that beat Nepal, seamer Luke Wood being replaced by Jamie Overton.
Wood conceded 14 runs from the 19th over against Nepal on Sunday in taking 1-31 from three overs.
England team to play West Indies: Phil Salt, Jos Buttler (wk), Jacob Bethell, Tom Banton, Harry Brook (capt), Sam Curran, Will Jacks, Liam Dawson, Jamie Overton, Jofra Archer, Adil Rashid