Cape Town - Pakistan fast bowler Usman Khan has been struck a cruel blow after it was discovered that he had suffered a stress fracture in his back.
Usman faces at least six months on the sidelines just weeks after making his ODI debut for Pakistan.
He tore through Sri Lanka in just his second match taking the fastest ever five wicket haul in ODI cricket and appeared set to add yet more firepower to the imposing Pakistan pace attack.
A screening after the T20I series against Sri Lanka confirmed a lumbar-bone stress fracture in his back.
Usman has been plagued by back injuries in his young career struggling with a similar problem back in 2013 and missing much of the 2014/15 season with back problems.
Pakistan head coach "It is disappointing but this [course of treatment] will give him the best chance of recovering as quickly as possible."
Usman's injury is the latest in a string to hit the Pakistan team with Mohammad Amir, Ruman Raees, Babar Azam and Imad Wasim all missing games recently.
When asked if he was concerned about the injuries Arthur said: "A little bit, but a lot of them niggles just needed a bit of rest and that is why we have put such a lot of effort in working on our bench strength."
Pakistan do not have a scheduled international engagement until their tour of New Zealand begins in January.