Nurul Hasan was named as Yasir’s concussion substitute, although he won’t be allowed to keep wickets
The incident occurred at the end of the 30th over when Yasir ducked into a Shaheen Shah Afridi bouncer. Yasir briefly took his eye away from the delivery while getting under the ball, and was hit on the helmet.
Bangladesh’s physio Bayejidul Islam checked Yasir immediately, and he went back to batting. But an over later, Bayejid came back to check on Yasir during the drinks break, after which he walked off.
The team director Khaled Mahmud informed a few minutes later that Yasir was out of the Test match, with Nurul as his replacement. Yasir has been taken to Imperial Hospital for a CT scan.
Mohammad Isam is ESPNcricinfo’s Bangladesh correspondent. @isam84