Having spent a few days off after helping Sunrisers Hyderabad to win the Indian Premier League crown, the 20-year-old sensation has returned to Dhaka, reports bdnews24.com.
His rehabilitation began from Thursday morning and he spent a long time with the physitherapists and trainers in the Bangladesh Cricket Board Academy gymnasium.
Speaking at a press conference later, the national team physio Bayezidul Islam said two things needed to be worked on.
"We are now working on the hamstring and the ankle injuries. The shoulder and side strain injuries have recovered," he said.
"We are thinking of assisting him every week and monitoring his improvement. We will take the next decision based on that assessment I don't see any possibility (of him playing) in the first week."
The left-arm seamer's physical condition will be reviewed eight days later and it is unlikely he will take the field at least in the next couple of weeks.
The news will come as a blow to Sussex who are keenly waiting for Mustafizur's arrival. They signed Mustafizur for this season's NatWest T20 Blast and Royal London One-Day Cup.
The team gave the ace bowler some time off after IPL to recover both physically and mentally. Captain Luke Wright was hoping to have Mustafizur in the match against Kent on Jun 10 at Hove.
But, with Mustafizur's current situation, it is unlikely that he will play the next match against Middlesex on Jun 16 and the uncertainty looms large over the following matches as well.