Mustafiz featured in Bangladesh's first ODI against Zimbabwe but bowled only six overs before missing the second match.
The Bangladesh Cricket Board (BCB) later confirmed that he had sustained a hamstring injury, with the medical team initially estimating a rehabilitation period of around four weeks upon his return home.
Despite the setback, Birmingham Phoenix called Mustafiz to England earlier this month to assess the extent of his injury ahead of the tournament. Following a series of medical examinations, the results were not encouraging.
The initial expectation was that the Bangladesh seamer might miss only the opening matches of The Hundred. However, Birmingham Phoenix have now confirmed that Mustafiz will miss the entire 2026 season. The franchise has yet to announce a replacement.
Mustafiz was set to make his debut in The Hundred after being signed by Birmingham Phoenix for his reserve price of £100,000 in March. He would have become the first Bangladeshi cricketer to feature in the 100-ball competition, but the injury has denied him that milestone.