The 19-year-old left-arm medium pacer created waves by becoming only the second bowler in ODI history to bag two five-wicket hauls in as many matches first up. Zimbabwe's Brian Vitori is the other player. But Streak cautioned that Mustafizur should be handled carefully to get the maximum out of the pacer in the long run.
"I think that's where as a coach you have to be careful not to over-coach and just help guide them along," Streak was quoted as saying by 'ESPNcricinfo'.
"He is still very young. We have to be careful. He has taken 11 wickets but we can't expect him to take five wickets every time. He has shown his potential. If we look after him and support him, he will be a big match-winner for us. When Mashrafe started, he was looked after throughout his career," the former Zimbabwe pacer added.
Mustafizur bowled the hosts to victory with his 5-50 in the first ODI and then produced another match-winning spell of 6-43 in the next game to give the Tigers their first bilateral series win against India. Streak though stressed on hard work and consistency for Mustafizur's longevity as a bowler.
"We discussed some other options (after the first ODI) if he didn't succeed with what he was doing in the first game, some variations that we might have to try to counteract it. India would have seen his video footage," he said.
The 41-year-old, who was appointed as bowling coach last year for a two-year period, said that the support staff, including coach Chandika Hathurusingha, are working hard to improve the fast bowling scene in the country.
"Mustafizur has been bowling well. We fought hard to get him into the T20 squad against Pakistan and he showed what he is capable of. Since then it has been good to have Mustafizur, Taskin (Ahmed) and Rubel (Hossian) who we know can perform.
"Mashrafe (Mortaza) has been a consistent performer for Bangladesh for a long time now. We have a good group and we felt India wouldn't expect that.
