England's batsmen have been swotting up on how to tackle Sri Lanka matchwinner Ajantha Mendis ahead of their initiation today.
Mendis, 24, has made mincemeat of teams in his first appearance against them, as South Africa discovered on Tuesday, and England are wary ahead of starting their own Champions Trophy campaign under Wanderers' floodlights today.
Although some of the current team faced him when he was a net bowler on the tour of Sri Lanka two years ago, they have not played the mystery spinner, whose 71 one-day international wickets come at intervals of just 22 deliveries, in a match situation.
"The guys have ideas," Flower said. "Seeing him for the first time is surprising, but our guys have had a good look of footage of him.
"They have also spoken to other people who have had success against him so they are as prepared as they can be without actually playing against him."
Such is his potency that the worry is batters become defensive to counter him.
"That is a danger," admitted Flower. "But I think batting is always a balance between attack and defence and each individual has to find that balance the best he can."
England begin the first of three Group B games in poor condition on the field, following a 6-1 thrashing by Australia, and also under-prepared for the altitude, according to Flower.
"I don't think the acclimatisation we have done is quite enough purely in physical terms," Flower said.
"But as soon as we arrived we had a little run out to test how our guys were reacting at altitude, and for them to feel it.
"To be honest that is the least of things on which we have to focus - we have got skills to deliver."
In addition to current form, there are further statistics which make sorry reading for England.
They have won just three of their past 11 meetings with Sri Lanka while their last eight one-day internationals on South African soil have reaped a solitary victory.
The only thing in their favour will perhaps be the pace of the pitch.
"There should be some bounce and seam in it, so it should be a wicket which is like ones the English guys play on a bit more than our guys," admitted Sri Lanka coach Trevor Bayliss.
"But our boys like the ball coming onto the bat and we are confident on any type of wicket.
"We have played some pretty good cricket over the past 18 months."