Ali Zakaria was hit in the eye and had to be taken to the Baptist Medical Center (BMC) for immediate treatment in an incident which has been described as exaggerated by the party's regional branch.
But Mr Zakaria had to be brought to Accra for further treatment.
Visiting him at the Dr Agarwal's Eye Hospital, Mr Kyerematen, who placed third in the weekend's elections after securing no votes in the North East Region, said the attack at the Nalerigu Senior High School constitutes a dent on the image of the NPP.
“We all joined the NPP because of our commitment to the values of our party but what is happening clearly shows that this is not what we bargained for,” he told journalists on Tuesday, August 29.
He warned that such behaviour will not be tolerated by him in the future.
“I am not going to tolerate this kind of behaviour. It doesn't make sense and when we cannot conduct ourselves as a family trying to select a leader in a peaceful and organised manner, how do we intend to be able to do the same kind of process when we have 200,000 plus people gathered?” he wondered concerning the November 4 Presidential Primary for the five qualified aspirants.
He said he is disturbed by the incident.
“Frankly, I am very disturbed about what has happened. The party must not put a shine on what has happened.”
The Elections Committee had earlier met him over the incident after he first complained about it in his statement issued right after the polls.
Despite stopping short of commenting on that meeting, Mr Kyerematen said: “What happened to my colleague on Saturday was an act of total indiscipline and indecent behaviour.
“How do we as a decent party going into an elections particularly at the level of super delegates superintend such behaviour?”