Mohammad Saad has become the first concussion substitute in the history of Pakistan domestic cricket. The middle-order batsman replaced Usman Salahuddin on day two of Central Punjab's Quaid-e-Azam Trophy match against Southern Punjab.

Salahuddin sustained a blow to the back of his neck on the first day of the match, while fielding at short leg. He was struck by a sweep from the opening batsman Sami Aslam.

Salahuddin appeared in some discomfort, but walked off the field himself, in the company of the Central Punjab physio. Scans confirmed a concussion, but ruled out any major concerns.

"The player was immediately examined for concussion and was taken off the field for an X-ray," the PCB said in a statement. "Salahuddin had neck pain, headache, and blurred vision immediately after injury."

Salahuddin was cleared to return to the dressing room but remained under observation. At the start of day two, Central Punjab requested the match referee that Saad be allowed to replace Salahuddin in their XI.

Salahuddin, 28, played two ODIs in May 2011 against West Indies, and got his maiden Test call-up six years later, on another tour of the Caribbean. He had to wait until June 2018 for his Test debut, against England at Headingley, where he scored 4 and 33 in an innings defeat. He has not featured in international cricket since.