Brendon McCullum has backed Jos Buttler to captain England back to white-ball prominence, insisting he is confident the 33-year-old is the right man to lead the limited-overs teams. But he also suggested Buttler has been hampered by the fact he is “not naturally as expressive as some may be” and “has been a bit miserable at times”.

McCullum said his own primary task as coach will be “to create an environment where guys feel positive, where they feel like they can allow their talent to come out”.

Buttler led England to victory at the 2022 T20 World Cup five months after taking over from Eoin Morgan, but has not been able to sustain that level of success, with the team ­enduring extremely disappointing 50- and 20-over tournaments in the past 10 months.

Those performances cost the white-ball coach, Matthew Mott, his job, with McCullum this week adding that role to his Test team duties. He officially takes over the white-ball sides in January.

“He’s done a great job,” McCullum said of Buttler. “He won a World Cup as captain. He’s an incredibly gifted player. He’s a fine leader.

“My job is to get the best out of him so that all those that sit in the dressing room feel like they can be 10ft tall and bulletproof when they walk out to play and they know that the skipper is going to enjoy the ride with them.

“What I want from Jos is for him to enjoy the next few years. If he was to retire today he’d go down as probably the greatest white-ball player England’s produced. So the opportunity for the next three or four years, however long he plays for, is just to enjoy it. Not to protect anything. Just get the most out of all those guys around him, keep walking towards the danger, play with a smile on his face and try to do something which is really cool, where you can look back and say: ‘Gee, I really enjoyed those last few years.’”

Buttler will not be able to reboot his captaincy just yet, after being ruled out of the T20 series against Australia, which starts next Wednesday, with a recurrence of the calf injury that has derailed his season. He has not played since England’s T20 World Cup semi-final loss to India in June, having picked up the injury during a beach run on holiday. He may also be ruled out of the ODI series against Australia that begins on 19 September.

Phil Salt, who has also understudied for Buttler as captain of Manchester Originals in the Hundred, will lead the T20 side, with Harry Brook pencilled in as his likely replacement for the ODIs. Jordan Cox, the uncapped Essex batter, has been added to the 50-over setup as cover and Surrey’s Jamie Overton, who is playing as a batter this summer while recovering from a lower back stress fracture, comes into the T20 squad.

After the third and final Test against Sri Lanka, which starts on Friday, with England seeking to complete a clean sweep of the summer for the second time since the 1950s, McCullum’s next task will be to prepare for a three-Test series against Pakistan. This is mired in uncertainty just over four weeks before it is due to begin.

The original schedule had the games being played in Multan, Karachi and Rawalpindi, but the stadium in Karachi is being rebuilt for February’s Champions Trophy and will not be finished in time. Alternative venues are being considered, reportedly including some that are not in Pakistan.

“We can’t pick a team until we know where we’re going to play,” McCullum said. “It would be nice if over the next couple of days we found out. Then we’ll sit down and make sure we’ve got the right team for the right conditions and the right opposition.”