With Jos Buttler and Adil Rashid injured, Joe Root was the only player in England’s XI for the third ODI against Sri Lanka with more than 50 caps.
England, who have struggled recently in 50-over cricket but have won three series in a row this year, have a minimum of 20 official ODIs before next year’s World Cup in southern Africa.
“Aside from Jos, Joe and Adil Rashid, there’s not a lot of experience in that side,” McCullum said after victory over Sri Lanka.
“We’re going to try and put on a smattering of warm-up games to try and get guys up to speed as quickly as we can.”
England are also due to play warm-ups before their Test tours of South Africa and Bangladesh this winter, and before the one-off 150th anniversary Test against Australia in Melbourne in March.
Those fixtures were in place before McCullum was replaced by Stephen Fleming as Test coach this summer.
Since the Ashes, the ECB and Cricket Australia have held discussions about a reciprocal arrangement that would mean touring teams are provided with better preparation before Ashes series.
England lost the first Ashes Test in Perth inside two days last year and were well beaten in the next two Tests to concede the series at the earliest opportunity. McCullum accepted afterwards mistakes may have been made with his side’s preparation.
England play three ODIs and five T20s in Australia this winter from 13 November to 2 December.
They also play a 50-over tri-series in Pakistan against the hosts and Sri Lanka later this month.
The announcement of England’s new batch of central contracts, meanwhile, is expected to come next week, having initially been anticipated at the start of October.