Former rugby league and soccer chief David Gallop will oversee the SCG, Stadium Australia and other major NSW stadia after Venues NSW chairman Morris Iemma suddenly fell ill.

Mr Iemma, a former Labor premier respected on both sides of politics, was appointed as chair of Venues NSW four weeks ago.

But a recent medical episode and the need for ongoing treatment meant the recent appointee resigned last Thursday, Sports Minister Steve Kamper said.

Mr Kamper did not detail the illness but wished him a speedy recovery.

"My first thoughts are with Morris and his family," he said on Monday.

"Out of respect for Mr Iemma and his family, I ask for their privacy to be respected so that Morris can recover and rehabilitate in peace."

Mr Iemma was appointed after a recruitment process that involved state officials and former International Olympic Committee vice president John Coates.

The sports minister said Mr Gallop was another "incredibly qualified" candidate identified during the recruitment process.

The sports administrator was NRL chief executive from 2002 to 2012 before a seven-year shift at the helm of Football Federation Australia, now known as Football Australia.

"David will bring valuable experience working with international organisations including FIFA and the Asian Football Confederation to the role," Mr Kamper said.