Matthews had received an offer from MultiChoice to take up a position with the satellite TV operators, Khoza said in a statement on Tuesday, confirming a report in a Sunday newspaper last week.
Matthews resigned in April, but Khoza asked him to stay on until the end of the recently concluded season.
"I remain committed to professional football in this country, and I'm willing to serve or try add value in any capacity in which I'm requested," Matthews said.
The PSL said league chief operations officer Cambridge Mokanyane would replace Matthews in an acting role.
Matthews, who started his term in February, is the second PSL chief executive to quit the job in the last nine months.
Zola Majavu stepped down in October – after two months in the post – due to "fundamental differences" with the PSL regarding his contract. – Sapa