Time to put on a show, says England skipper Morgan
Morgan said he had become well aware of the importance of live televised sport during the lockdown imposed by Covid-19.
"It's huge," he said of the chance to play international sport and provide entertainment for viewers.
But Morgan said he did not foresee an early end to the need for teams to remain in bio-secure "bubbles" while playing.
"There's news about vaccines but the first to receive it will be the people who really need it. We are well down the pecking order of who should be prioritised," he said.
"I don't see any change before the start of our own summer."
England have further winter tours planned to Sri Lanka and India before then.
"It's the first time in a long time we've had a full-strength team available for selection. It's very exciting."
He said he believed his team were well prepared, with some players having been active in the recent Indian Premier League while others had benefited from an extended off-season rest.
"Training was very dangerous," he joked about England's big-hitting batsmen flexing their muscles in practice. "We had open nets and balls were flying about."
South Africa captain Quinton de Kock said his country's large 24-man squad had been picked to cover both the T20 series and a one-day international series immediately afterwards.
"We will narrow it down to 12 or 13 when we get to the ground today," he said.
Two unnamed South African players remain in isolation after testing positive for Covid-19 but Cricket South Africa announced on Thursday there had been no new positive cases after a third round of testing.
However, all-rounder Dwaine Pretorius had been ruled out of both series after suffering a hamstring injury during training.
De Kock said: "England have an unbelievable team full of match-winners, but in the last series we gave them a run for their money so I expect a close series."
Morgan echoed De Kock's thoughts.
"I expect an extremely competitive series," he said, pointing out that earlier in the year the two sides had drawn a one-day series in South Africa before England narrowly won a T20 series.