The Black Caps were thrashed 2-0 by the top-ranked South Africa, who won both the games with big margins.
“There’s no point discarding these players and then going through the same process all over again,” McCullum told SuperSport.
“There needs to be a little bit of change at some point but it’s important to protect the core of this group because they’re the ones who had the opportunity to learn from the very best,” he added.
McCullum accepted that his side had no answer to the South African pace attack comprising Dale Steyn, Morne Morel and Vernon Philander, after defeat in the recently-concluded Test series.
“We have never been challenged like that at the crease so consistently from a group of bowlers and it was as hard as you get in international cricket,” McCullum said.
“They give you no scoring opportunities and my role at the top of the order is very much about trying to take some sting out of the new ball.”
“Three times I got through the tough periods and three times I was dismissed by Robin Peterson. So that’s frustrating but I have no doubt whatsoever that the approach was right and we saw that twice when we took the sting out of the new ball – the middle order batsmen we have were able to prosper,” he added.