Tuesday is ahead of England's World Cup campaign against South Africa on October 3, with a 50-point format in a 50-point format.
Regular criticism of England in recent years is their ability to win bilateral series outside the World Cup, but lose pressure in the main matches.
They lost to South Africa in the semifinals of the 2023 T20 World Cup and withdrew from last year's match in the group stage after a collapse in the full match against the West Indies.
Tuesday's decision-makers will be as close as possible to these moments outside of global events.
“We've seen that the bilateral series does, but when we go to the World Cup or the Championship, we don't have momentum or clinical at those stressful moments,” Dean said.
“Whether there is a chance, we can imitate the bilateral series is the perfect practice.
“Obviously, we want to win, but even if we don't, we can take these learnings and keep getting better and get ourselves started with a 50 win competition. That's the most important thing.
“No matter how we play tomorrow, we really reflect and learn from the situation.”