Mohammad Rizwan has replaced Sarfaraz Ahmed in the ongoing 2nd Test between Sri Lanka and Pakistan.
Pakistan are currently 476 for 5, in reply to Sri Lanka's 166 in the first innings. But during Pakistan's batting on Wednesday (July 26), Sarfaraz Ahmed was hit on the head in the bowling of Asitha Fernando.

The Pakistan keeper went to duck a bouncer from the Sri Lankan pacer and was hit on the head. Ahmed was batting on 14 off 22 balls, but couldn't continue due to a concussion.
The 36-year-old was retired hurt and was taken off the field. And now Pakistan team management requested for a concussion substitution, which has been accepted by match referee David Boon.
PCB confirmed in a statement that Mohammad Rizwan has replaced Sarfaraz Ahmed as a concussion substitute.
"Sarfaraz Ahmed has been replaced by Mohammad Rizwan as a concussion substitute in the ongoing second Test between Pakistan and Sri Lanka at the Singhalese Sports Club after match referee David Boon accepted the Pakistan team management's request for the substitution," a statement from PCB read.
Yes, as the protocol of a concussion substitute, the incoming player can both bat and ball in the match. And as a matter of fact, Mohammad Rizwan is currently batting and is along with Agha Salman at the crease.