Mustafizur Rahman being nowhere near his usual best is no longer a topic of debate, but the left-arm quick will still remain the most vital component in the Bangladesh pace battery in the upcoming ICC T20 World Cup in Australia next month.

The 27-year-old is undoubtedly an auto-choice as the most experienced bowler in the Tigers T20I setup. However, he now has the additional responsibility of guiding the likes of Taskin Ahmed, Mohammad Saifuddin, Hasan Mahmud and Ebadot Hossain -- who are certain to feel the heat at the biggest stage.

Mustafizur emerged as a mystery bowler since making his international debut back in 2015. With his unique cutters and slower deliveries, he made a strong impression in the franchise-based T20 leagues around the world.

Unfortunately, for Bangladesh, the cricketer from Satkhira just could not live up to his expectations as his growth-curve had apparently flattened over the past few years. Mustafizur's economy-rate has remained a big concern and his inability to absorb pressure in critical situations had wounded the Tigers on several occasions, as was evident in the recently concluded Asia Cup.

"Mustafizur is very effective in Bangladesh but I don't think he will get such assistance in Australian conditions," senior pace-bowling coach Sarwar Imran told The Daily Star yesterday.

"Another very important aspect is that Mustafizur lacks accuracy which is required at the international circuit. He has turned predictable as his lengths and his cutters are not as effective as before.

"At the beginning, his unique slowers surprised the batters. But since every team have computer analysts nowadays, they can do their homework on him," he added.

It will be important for 'Fizz' to involve variety in his armoury but Imran also pointed at the tendency of Mustafizur and Co's over-reliance on coaches.

"He was unable to add variations in his arsenal, and one of those were making the ball cut in to the right-hander. Mustafizur might do that with the new ball but it seems tough for him at the moment with the old ball in the death overs. I haven't seen him trying those yorkers for a long time now.

"I think our main problem is that we are fully dependent on the coaches, officials and the god fathers. Every time a new coach comes from abroad and starts imposing their own philosophy on Mustafizur. But what is important is whether Mustafizur follows his own training method and prepares himself accordingly to make him better," Sarwar continued.

"Mustafizur and the South African pacer Kagiso Rabada made their international debut at the same period and look at the difference. Look, he has reached the peak and became one of the top bowlers in world cricket in T20 format but he never developed his personality to that level," he added further.

Imran also urged Mustafizur to develop his reading of the game, as someone who could set his own field positions and bowl according to his plan in the Australian conditions.

"A good bowler will always set his own field positions. Tell me which bowler in our team sets his own fielding? I think this is one of those areas we need to fix as well," Sarwar concluded.